1340720640 has 640 divisors, whose sum is σ = 5798200320. Its totient is φ = 286654464.

The previous prime is 1340720629. The next prime is 1340720651. The reversal of 1340720640 is 460270431.

1340720640 is a `hidden beast` number, since 13 + 4 + 0 + 7 + 2 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (1340720629) and next prime (1340720651).

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8225199 + ... + 8225361.

It is an arithmetic number, because the mean of its divisors is an integer number (9059688).

Almost surely, 2^1340720640 is an apocalyptic number.

1340720640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1340720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2899100160).

1340720640 is an abundant number, since it is smaller than the sum of its proper divisors (4457479680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1340720640 is a wasteful number, since it uses less digits than its factorization.

1340720640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 1340720640 is about 36615.8523047054. The cubic root of 1340720640 is about 1102.6713695389.

1340720640 divided by its product of nonzero digits (4032) gives a triangular number (332520 = T₈₁₅).

The spelling of 1340720640 in words is "one billion, three hundred forty million, seven hundred twenty thousand, six hundred forty".