21858517124377 has 4 divisors (see below), whose sum is σ = 21884570184960. Its totient is φ = 21832464063796.

The previous prime is 21858517124261. The next prime is 21858517124383. The reversal of 21858517124377 is 77342171585812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21858517124377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21858517124387) 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 3 ways as a sum of consecutive naturals, for example, 13026529033 + ... + 13026530710.

It is an arithmetic number, because the mean of its divisors is an integer number (5471142546240).

Almost surely, 2^{21858517124377} is an apocalyptic number.

It is an amenable number.

21858517124377 is a deficient number, since it is larger than the sum of its proper divisors (26053060583).

21858517124377 is an equidigital number, since it uses as much as digits as its factorization.

21858517124377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26053060582.

The product of its digits is 26342400, while the sum is 61.

The spelling of 21858517124377 in words is "twenty-one trillion, eight hundred fifty-eight billion, five hundred seventeen million, one hundred twenty-four thousand, three hundred seventy-seven".