21154812075 has 36 divisors (see below), whose sum is σ = 38258530960. Its totient is φ = 11173014720.

The previous prime is 21154812047. The next prime is 21154812079. The reversal of 21154812075 is 57021845112.

It is a happy number.

21154812075 is a `hidden beast` number, since 21 + 1 + 548 + 1 + 20 + 75 = 666.

It is not a de Polignac number, because 21154812075 - 2⁷ = 21154811947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21154812079) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 433240 + ... + 479589.

Almost surely, 2^21154812075 is an apocalyptic number.

21154812075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21154812075 is a deficient number, since it is larger than the sum of its proper divisors (17103718885).

21154812075 is a wasteful number, since it uses less digits than its factorization.

21154812075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912948 (or 912940 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The spelling of 21154812075 in words is "twenty-one billion, one hundred fifty-four million, eight hundred twelve thousand, seventy-five".