1640121140 has 72 divisors (see below), whose sum is σ = 4066544160. Its totient is φ = 553912128.

The previous prime is 1640121113. The next prime is 1640121143. The reversal of 1640121140 is 411210461.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640121143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53171 + ... + 78149.

It is an arithmetic number, because the mean of its divisors is an integer number (56479780).

Almost surely, 2^1640121140 is an apocalyptic number.

1640121140 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 1640121140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2033272080).

1640121140 is an abundant number, since it is smaller than the sum of its proper divisors (2426423020).

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

1640121140 is a wasteful number, since it uses less digits than its factorization.

1640121140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25069 (or 25060 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1640121140 is about 40498.4091045562. The cubic root of 1640121140 is about 1179.3027432989.

The spelling of 1640121140 in words is "one billion, six hundred forty million, one hundred twenty-one thousand, one hundred forty".