21651534150540 has 48 divisors (see below), whose sum is σ = 69284909283072. Its totient is φ = 4948922091456.

The previous prime is 21651534150527. The next prime is 21651534150599. The reversal of 21651534150540 is 4505143515612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 21651534150492 and 21651534150501.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25775635474 + ... + 25775636313.

It is an arithmetic number, because the mean of its divisors is an integer number (1443435610064).

Almost surely, 2^{21651534150540} is an apocalyptic number.

21651534150540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21651534150540 is an abundant number, since it is smaller than the sum of its proper divisors (47633375132532).

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

21651534150540 is a wasteful number, since it uses less digits than its factorization.

21651534150540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51551271806 (or 51551271804 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 42.

The spelling of 21651534150540 in words is "twenty-one trillion, six hundred fifty-one billion, five hundred thirty-four million, one hundred fifty thousand, five hundred forty".