21531315354 has 64 divisors (see below), whose sum is σ = 47392926336. Its totient is φ = 6493077504.

The previous prime is 21531315347. The next prime is 21531315359. The reversal of 21531315354 is 45351313512.

It is a super-2 number, since 2×21531315354² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21531315359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 278874 + ... + 347610.

It is an arithmetic number, because the mean of its divisors is an integer number (740514474).

Almost surely, 2^21531315354 is an apocalyptic number.

21531315354 is an abundant number, since it is smaller than the sum of its proper divisors (25861610982).

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

21531315354 is a wasteful number, since it uses less digits than its factorization.

21531315354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68879.

The product of its digits is 27000, while the sum is 33.

Adding to 21531315354 its reverse (45351313512), we get a palindrome (66882628866).

The spelling of 21531315354 in words is "twenty-one billion, five hundred thirty-one million, three hundred fifteen thousand, three hundred fifty-four".