21377639849 has 4 divisors (see below), whose sum is σ = 21678733440. Its totient is φ = 21076546260.

The previous prime is 21377639839. The next prime is 21377639863. The reversal of 21377639849 is 94893677312.

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 not a de Polignac number, because 21377639849 - 2³² = 17082672553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21377639839) 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, 150546689 + ... + 150546830.

It is an arithmetic number, because the mean of its divisors is an integer number (5419683360).

Almost surely, 2^21377639849 is an apocalyptic number.

It is an amenable number.

21377639849 is a deficient number, since it is larger than the sum of its proper divisors (301093591).

21377639849 is an equidigital number, since it uses as much as digits as its factorization.

21377639849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301093590.

The product of its digits is 13716864, while the sum is 59.

The spelling of 21377639849 in words is "twenty-one billion, three hundred seventy-seven million, six hundred thirty-nine thousand, eight hundred forty-nine".