21549399747008 has 112 divisors (see below), whose sum is σ = 51748023040704. Its totient is φ = 8691808419840.

The previous prime is 21549399746933. The next prime is 21549399747019. The reversal of 21549399747008 is 80074799394512.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (68).

It is a congruent number.

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 in 15 ways as a sum of consecutive naturals, for example, 223351898 + ... + 223448358.

Almost surely, 2^{21549399747008} is an apocalyptic number.

21549399747008 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21549399747008 is an abundant number, since it is smaller than the sum of its proper divisors (30198623293696).

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

21549399747008 is a wasteful number, since it uses less digits than its factorization.

21549399747008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125830 (or 125820 counting only the distinct ones).

The product of its (nonzero) digits is 137168640, while the sum is 68.

The spelling of 21549399747008 in words is "twenty-one trillion, five hundred forty-nine billion, three hundred ninety-nine million, seven hundred forty-seven thousand, eight".