21135512614660 has 24 divisors (see below), whose sum is σ = 44425036497240. Its totient is φ = 8446498377984.

The previous prime is 21135512614631. The next prime is 21135512614663. The reversal of 21135512614660 is 6641621553112.

It can be written as a sum of positive squares in 4 ways, for example, as 2191151904516 + 18944360710144 = 1480254^2 + 4352512^2 .

It is not an unprimeable number, because it can be changed into a prime (21135512614663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 481644255 + ... + 481688134.

It is an arithmetic number, because the mean of its divisors is an integer number (1851043187385).

Almost surely, 2^{21135512614660} is an apocalyptic number.

21135512614660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21135512614660 is an abundant number, since it is smaller than the sum of its proper divisors (23289523882580).

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

21135512614660 is a wasteful number, since it uses less digits than its factorization.

21135512614660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 963333495 (or 963333493 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 21135512614660 in words is "twenty-one trillion, one hundred thirty-five billion, five hundred twelve million, six hundred fourteen thousand, six hundred sixty".