21255296940 has 96 divisors (see below), whose sum is σ = 68260792320. Its totient is φ = 5485233600.

The previous prime is 21255296893. The next prime is 21255296963. The reversal of 21255296940 is 4969255212.

21255296940 is a `hidden beast` number, since 2 + 1 + 2 + 552 + 9 + 6 + 94 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 618126 + ... + 651605.

It is an arithmetic number, because the mean of its divisors is an integer number (711049920).

Almost surely, 2^21255296940 is an apocalyptic number.

21255296940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21255296940 is an abundant number, since it is smaller than the sum of its proper divisors (47005495380).

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

21255296940 is a wasteful number, since it uses less digits than its factorization.

21255296940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269780 (or 1269772 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 21255296940 in words is "twenty-one billion, two hundred fifty-five million, two hundred ninety-six thousand, nine hundred forty".