21436557700 has 18 divisors (see below), whose sum is σ = 46517330426. Its totient is φ = 8574623040.

The previous prime is 21436557697. The next prime is 21436557787. The reversal of 21436557700 is 775563412.

It can be written as a sum of positive squares in 3 ways, for example, as 63872064 + 21372685636 = 7992^2 + 146194^2 .

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, 107182689 + ... + 107182888.

Almost surely, 2^21436557700 is an apocalyptic number.

21436557700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21436557700 is an abundant number, since it is smaller than the sum of its proper divisors (25080772726).

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

21436557700 is a wasteful number, since it uses less digits than its factorization.

21436557700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214365591 (or 214365584 counting only the distinct ones).

The product of its (nonzero) digits is 176400, while the sum is 40.

The spelling of 21436557700 in words is "twenty-one billion, four hundred thirty-six million, five hundred fifty-seven thousand, seven hundred".