21320540534 has 16 divisors (see below), whose sum is σ = 32711827968. Its totient is φ = 10417300392.

The previous prime is 21320540491. The next prime is 21320540551. The reversal of 21320540534 is 43504502312.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21320540497 and 21320540506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114464 + ... + 236099.

It is an arithmetic number, because the mean of its divisors is an integer number (2044489248).

Almost surely, 2^21320540534 is an apocalyptic number.

21320540534 is a deficient number, since it is larger than the sum of its proper divisors (11391287434).

21320540534 is a wasteful number, since it uses less digits than its factorization.

21320540534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351259.

The product of its (nonzero) digits is 14400, while the sum is 29.

The spelling of 21320540534 in words is "twenty-one billion, three hundred twenty million, five hundred forty thousand, five hundred thirty-four".