21381257466 has 48 divisors (see below), whose sum is σ = 46801317888. Its totient is φ = 7054236000.

The previous prime is 21381257461. The next prime is 21381257483. The reversal of 21381257466 is 66475218312.

21381257466 is a `hidden beast` number, since 2 + 1 + 3 + 8 + 12 + 574 + 66 = 666.

It is not an unprimeable number, because it can be changed into a prime (21381257461) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 974416 + ... + 996116.

It is an arithmetic number, because the mean of its divisors is an integer number (975027456).

Almost surely, 2^21381257466 is an apocalyptic number.

21381257466 is an abundant number, since it is smaller than the sum of its proper divisors (25420060422).

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

21381257466 is a wasteful number, since it uses less digits than its factorization.

21381257466 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22267 (or 22264 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21381257466 in words is "twenty-one billion, three hundred eighty-one million, two hundred fifty-seven thousand, four hundred sixty-six".