21753878151 has 4 divisors (see below), whose sum is σ = 29005170872. Its totient is φ = 14502585432.

The previous prime is 21753878119. The next prime is 21753878171. The reversal of 21753878151 is 15187835712.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21753878151 - 2⁵ = 21753878119 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21753878151.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21753878171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3625646356 + ... + 3625646361.

It is an arithmetic number, because the mean of its divisors is an integer number (7251292718).

Almost surely, 2^21753878151 is an apocalyptic number.

21753878151 is a deficient number, since it is larger than the sum of its proper divisors (7251292721).

21753878151 is an equidigital number, since it uses as much as digits as its factorization.

21753878151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7251292720.

The product of its digits is 470400, while the sum is 48.

The spelling of 21753878151 in words is "twenty-one billion, seven hundred fifty-three million, eight hundred seventy-eight thousand, one hundred fifty-one".