21306681036 has 18 divisors (see below), whose sum is σ = 53858554932. Its totient is φ = 7102227000.

The previous prime is 21306680971. The next prime is 21306681047. The reversal of 21306681036 is 63018660312.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 591852251 = 21306681036 / (2 + 1 + 3 + 0 + 6 + 6 + 8 + 1 + 0 + 3 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 295926090 + ... + 295926161.

Almost surely, 2^21306681036 is an apocalyptic number.

It is an amenable number.

21306681036 is an abundant number, since it is smaller than the sum of its proper divisors (32551873896).

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

21306681036 is a wasteful number, since it uses less digits than its factorization.

21306681036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591852261 (or 591852256 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 21306681036 in words is "twenty-one billion, three hundred six million, six hundred eighty-one thousand, thirty-six".