21873639707 has 2 divisors, whose sum is σ = 21873639708. Its totient is φ = 21873639706.

The previous prime is 21873639703. The next prime is 21873639899. The reversal of 21873639707 is 70793637812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21873639707 - 2² = 21873639703 is a prime.

It is a super-2 number, since 2×21873639707² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21873639703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936819853 + 10936819854.

It is an arithmetic number, because the mean of its divisors is an integer number (10936819854).

Almost surely, 2^21873639707 is an apocalyptic number.

21873639707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873639707 is an equidigital number, since it uses as much as digits as its factorization.

21873639707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2667168, while the sum is 53.

The spelling of 21873639707 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-nine thousand, seven hundred seven".