21531204523410 has 64 divisors (see below), whose sum is σ = 52675408183680. Its totient is φ = 5631364753920.

The previous prime is 21531204523267. The next prime is 21531204523417. The reversal of 21531204523410 is 1432540213512.

It is a super-2 number, since 2×21531204523410² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21531204523417) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27070561 + ... + 27854580.

It is an arithmetic number, because the mean of its divisors is an integer number (823053252870).

Almost surely, 2^{21531204523410} is an apocalyptic number.

21531204523410 is an abundant number, since it is smaller than the sum of its proper divisors (31144203660270).

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

21531204523410 is a wasteful number, since it uses less digits than its factorization.

21531204523410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54925403.

The product of its (nonzero) digits is 28800, while the sum is 33.

Adding to 21531204523410 its reverse (1432540213512), we get a palindrome (22963744736922).

The spelling of 21531204523410 in words is "twenty-one trillion, five hundred thirty-one billion, two hundred four million, five hundred twenty-three thousand, four hundred ten".