21340369956 has 36 divisors (see below), whose sum is σ = 52053306032. Its totient is φ = 6804173904.

The previous prime is 21340369951. The next prime is 21340369957. The reversal of 21340369956 is 65996304312.

It is a super-2 number, since 2×21340369956² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21340369951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1674526 + ... + 1687221.

Almost surely, 2^21340369956 is an apocalyptic number.

It is an amenable number.

21340369956 is an abundant number, since it is smaller than the sum of its proper divisors (30712936076).

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

21340369956 is a wasteful number, since it uses less digits than its factorization.

21340369956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361800 (or 3361775 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 48.

The spelling of 21340369956 in words is "twenty-one billion, three hundred forty million, three hundred sixty-nine thousand, nine hundred fifty-six".