21015198432 has 72 divisors (see below), whose sum is σ = 61377190056. Its totient is φ = 6815736576.

The previous prime is 21015198427. The next prime is 21015198439. The reversal of 21015198432 is 23489151012.

21015198432 is a `hidden beast` number, since 2 + 101 + 519 + 8 + 4 + 32 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015198439) 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 11 ways as a sum of consecutive naturals, for example, 975418 + ... + 996729.

It is an arithmetic number, because the mean of its divisors is an integer number (852460973).

Almost surely, 2^21015198432 is an apocalyptic number.

It is an amenable number.

21015198432 is an abundant number, since it is smaller than the sum of its proper divisors (40361991624).

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

21015198432 is a wasteful number, since it uses less digits than its factorization.

21015198432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1972200 (or 1972189 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 21015198432 in words is "twenty-one billion, fifteen million, one hundred ninety-eight thousand, four hundred thirty-two".