21507051540534 has 32 divisors (see below), whose sum is σ = 49751251764480. Its totient is φ = 6070837266912.

The previous prime is 21507051540521. The next prime is 21507051540553. The reversal of 21507051540534 is 43504515070512.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3084771549 + ... + 3084778520.

It is an arithmetic number, because the mean of its divisors is an integer number (1554726617640).

Almost surely, 2^{21507051540534} is an apocalyptic number.

21507051540534 is an abundant number, since it is smaller than the sum of its proper divisors (28244200223946).

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

21507051540534 is a wasteful number, since it uses less digits than its factorization.

21507051540534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6169550164.

The product of its (nonzero) digits is 420000, while the sum is 42.

The spelling of 21507051540534 in words is "twenty-one trillion, five hundred seven billion, fifty-one million, five hundred forty thousand, five hundred thirty-four".