21151012164 has 12 divisors (see below), whose sum is σ = 49352361744. Its totient is φ = 7050337384.

The previous prime is 21151012151. The next prime is 21151012171. The reversal of 21151012164 is 46121015112.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881292162 + ... + 881292185.

It is an arithmetic number, because the mean of its divisors is an integer number (4112696812).

Almost surely, 2^21151012164 is an apocalyptic number.

It is an amenable number.

21151012164 is an abundant number, since it is smaller than the sum of its proper divisors (28201349580).

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

21151012164 is a wasteful number, since it uses less digits than its factorization.

21151012164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762584354 (or 1762584352 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

Adding to 21151012164 its reverse (46121015112), we get a palindrome (67272027276).

The spelling of 21151012164 in words is "twenty-one billion, one hundred fifty-one million, twelve thousand, one hundred sixty-four".