21135762440 has 64 divisors (see below), whose sum is σ = 51230188800. Its totient is φ = 7801443072.

The previous prime is 21135762409. The next prime is 21135762457. The reversal of 21135762440 is 4426753112.

It is a super-2 number, since 2×21135762440² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21135762440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2553749 + ... + 2562011.

It is an arithmetic number, because the mean of its divisors is an integer number (800471700).

Almost surely, 2^21135762440 is an apocalyptic number.

21135762440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21135762440 is an abundant number, since it is smaller than the sum of its proper divisors (30094426360).

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

21135762440 is a wasteful number, since it uses less digits than its factorization.

21135762440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13206 (or 13202 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The spelling of 21135762440 in words is "twenty-one billion, one hundred thirty-five million, seven hundred sixty-two thousand, four hundred forty".