21545541200 has 60 divisors (see below), whose sum is σ = 52472318268. Its totient is φ = 8500147200.

The previous prime is 21545541197. The next prime is 21545541223. The reversal of 21545541200 is 214554512.

It can be written as a sum of positive squares in 6 ways, for example, as 1812034624 + 19733506576 = 42568^2 + 140476^2 .

It is a congruent number.

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, 339731 + ... + 398130.

Almost surely, 2^21545541200 is an apocalyptic number.

21545541200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21545541200 is an abundant number, since it is smaller than the sum of its proper divisors (30926777068).

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

21545541200 is a wasteful number, since it uses less digits than its factorization.

21545541200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737952 (or 737941 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 29.

The spelling of 21545541200 in words is "twenty-one billion, five hundred forty-five million, five hundred forty-one thousand, two hundred".