21858957955 has 4 divisors (see below), whose sum is σ = 26230749552. Its totient is φ = 17487166360.

The previous prime is 21858957943. The next prime is 21858958007. The reversal of 21858957955 is 55975985812.

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

It is not a de Polignac number, because 21858957955 - 2¹⁷ = 21858826883 is a prime.

It is a super-3 number, since 3×21858957955³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2185895791 + ... + 2185895800.

It is an arithmetic number, because the mean of its divisors is an integer number (6557687388).

Almost surely, 2^21858957955 is an apocalyptic number.

21858957955 is a deficient number, since it is larger than the sum of its proper divisors (4371791597).

21858957955 is an equidigital number, since it uses as much as digits as its factorization.

21858957955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4371791596.

The product of its digits is 45360000, while the sum is 64.

The spelling of 21858957955 in words is "twenty-one billion, eight hundred fifty-eight million, nine hundred fifty-seven thousand, nine hundred fifty-five".