21510271551516 has 96 divisors (see below), whose sum is σ = 57346398144000. Its totient is φ = 6211683160320.

The previous prime is 21510271551499. The next prime is 21510271551547. The reversal of 21510271551516 is 61515517201512.

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 31 ways as a sum of consecutive naturals, for example, 12352591 + ... + 13985958.

It is an arithmetic number, because the mean of its divisors is an integer number (597358314000).

Almost surely, 2^{21510271551516} is an apocalyptic number.

It is an amenable number.

21510271551516 is an abundant number, since it is smaller than the sum of its proper divisors (35836126592484).

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

21510271551516 is a wasteful number, since it uses less digits than its factorization.

21510271551516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26338859 (or 26338857 counting only the distinct ones).

The product of its (nonzero) digits is 105000, while the sum is 42.

The spelling of 21510271551516 in words is "twenty-one trillion, five hundred ten billion, two hundred seventy-one million, five hundred fifty-one thousand, five hundred sixteen".