21521005031140 has 24 divisors (see below), whose sum is σ = 47852587658232. Its totient is φ = 8102025423360.

The previous prime is 21521005031131. The next prime is 21521005031159. The reversal of 21521005031140 is 4113050012512.

It can be written as a sum of positive squares in 4 ways, for example, as 4058234424036 + 17462770607104 = 2014506^2 + 4178848^2 .

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, 31648536471 + ... + 31648537150.

It is an arithmetic number, because the mean of its divisors is an integer number (1993857819093).

Almost surely, 2^{21521005031140} is an apocalyptic number.

21521005031140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21521005031140 is an abundant number, since it is smaller than the sum of its proper divisors (26331582627092).

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

21521005031140 is a wasteful number, since it uses less digits than its factorization.

21521005031140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63297073647 (or 63297073645 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 21521005031140 its reverse (4113050012512), we get a palindrome (25634055043652).

The spelling of 21521005031140 in words is "twenty-one trillion, five hundred twenty-one billion, five million, thirty-one thousand, one hundred forty".