21397532236 has 6 divisors (see below), whose sum is σ = 37445681420. Its totient is φ = 10698766116.

The previous prime is 21397532227. The next prime is 21397532249. The reversal of 21397532236 is 63223579312.

It is a junction number, because it is equal to n+sod(n) for n = 21397532192 and 21397532201.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2674691526 + ... + 2674691533.

Almost surely, 2^21397532236 is an apocalyptic number.

It is an amenable number.

21397532236 is a deficient number, since it is larger than the sum of its proper divisors (16048149184).

21397532236 is a wasteful number, since it uses less digits than its factorization.

21397532236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5349383063 (or 5349383061 counting only the distinct ones).

The product of its digits is 408240, while the sum is 43.

The spelling of 21397532236 in words is "twenty-one billion, three hundred ninety-seven million, five hundred thirty-two thousand, two hundred thirty-six".