1264191840 has 192 divisors, whose sum is σ = 4442558400. Its totient is φ = 335757312.

The previous prime is 1264191833. The next prime is 1264191857. The reversal of 1264191840 is 481914621.

1264191840 is a `hidden beast` number, since 1 + 2 + 641 + 9 + 1 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1264191795 and 1264191804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1524546 + ... + 1525374.

It is an arithmetic number, because the mean of its divisors is an integer number (23138325).

Almost surely, 2^1264191840 is an apocalyptic number.

1264191840 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 1264191840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2221279200).

1264191840 is an abundant number, since it is smaller than the sum of its proper divisors (3178366560).

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

1264191840 is a wasteful number, since it uses less digits than its factorization.

1264191840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206 (or 1192 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1264191840 is about 35555.4755276877. The cubic root of 1264191840 is about 1081.2787322825.

The spelling of 1264191840 in words is "one billion, two hundred sixty-four million, one hundred ninety-one thousand, eight hundred forty".