21254623236 has 120 divisors (see below), whose sum is σ = 69274408896. Its totient is φ = 5520674880.

The previous prime is 21254623211. The next prime is 21254623237. The reversal of 21254623236 is 63232645212.

21254623236 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 4 + 623 + 23 + 6 = 666.

It is a super-2 number, since 2×21254623236² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21254623236.

It is not an unprimeable number, because it can be changed into a prime (21254623237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 401031 + ... + 450926.

Almost surely, 2^21254623236 is an apocalyptic number.

It is an amenable number.

21254623236 is an abundant number, since it is smaller than the sum of its proper divisors (48019785660).

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

21254623236 is a wasteful number, since it uses less digits than its factorization.

21254623236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851991 (or 851980 counting only the distinct ones).

The product of its digits is 103680, while the sum is 36.

It can be divided in two parts, 2125 and 4623236, that added together give a triangular number (4625361 = T₃₀₄₁).

The spelling of 21254623236 in words is "twenty-one billion, two hundred fifty-four million, six hundred twenty-three thousand, two hundred thirty-six".