21009311046 has 24 divisors (see below), whose sum is σ = 46488690144. Its totient is φ = 6854101200.

The previous prime is 21009311033. The next prime is 21009311101. The reversal of 21009311046 is 64011390012.

It is a super-2 number, since 2×21009311046² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12416005 + ... + 12417696.

It is an arithmetic number, because the mean of its divisors is an integer number (1937028756).

Almost surely, 2^21009311046 is an apocalyptic number.

21009311046 is an abundant number, since it is smaller than the sum of its proper divisors (25479379098).

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

21009311046 is a wasteful number, since it uses less digits than its factorization.

21009311046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24833756 (or 24833753 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The spelling of 21009311046 in words is "twenty-one billion, nine million, three hundred eleven thousand, forty-six".