21021014251240 has 16 divisors (see below), whose sum is σ = 47297282065380. Its totient is φ = 8408405700480.

The previous prime is 21021014251217. The next prime is 21021014251243. The reversal of 21021014251240 is 4215241012012.

It can be written as a sum of positive squares in 2 ways, for example, as 18262750968036 + 2758263283204 = 4273494^2 + 1660802^2 .

It is not an unprimeable number, because it can be changed into a prime (21021014251243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262762678101 + ... + 262762678180.

Almost surely, 2^{21021014251240} is an apocalyptic number.

21021014251240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021014251240 is an abundant number, since it is smaller than the sum of its proper divisors (26276267814140).

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

21021014251240 is a wasteful number, since it uses less digits than its factorization.

21021014251240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525525356292 (or 525525356288 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 25.

Adding to 21021014251240 its reverse (4215241012012), we get a palindrome (25236255263252).

The spelling of 21021014251240 in words is "twenty-one trillion, twenty-one billion, fourteen million, two hundred fifty-one thousand, two hundred forty".