21240136620 has 36 divisors (see below), whose sum is σ = 64428414960. Its totient is φ = 5664036384.

The previous prime is 21240136597. The next prime is 21240136661. The reversal of 21240136620 is 2663104212.

21240136620 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 0 + 1 + 36 + 620 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21240136620² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59000200 + ... + 59000559.

Almost surely, 2^21240136620 is an apocalyptic number.

21240136620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21240136620 is an abundant number, since it is smaller than the sum of its proper divisors (43188278340).

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

21240136620 is a wasteful number, since it uses less digits than its factorization.

21240136620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118000774 (or 118000769 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The spelling of 21240136620 in words is "twenty-one billion, two hundred forty million, one hundred thirty-six thousand, six hundred twenty".