21521135310 has 16 divisors (see below), whose sum is σ = 51650724816. Its totient is φ = 5738969408.

The previous prime is 21521135309. The next prime is 21521135333. The reversal of 21521135310 is 1353112512.

It is a super-2 number, since 2×21521135310² (a number of 21 digits) contains 22 as substring.

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, 358685559 + ... + 358685618.

It is an arithmetic number, because the mean of its divisors is an integer number (3228170301).

Almost surely, 2^21521135310 is an apocalyptic number.

21521135310 is an abundant number, since it is smaller than the sum of its proper divisors (30129589506).

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

21521135310 is a wasteful number, since it uses less digits than its factorization.

21521135310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717371187.

The product of its (nonzero) digits is 900, while the sum is 24.

Adding to 21521135310 its reverse (1353112512), we get a palindrome (22874247822).

The spelling of 21521135310 in words is "twenty-one billion, five hundred twenty-one million, one hundred thirty-five thousand, three hundred ten".