21780522307 has 2 divisors, whose sum is σ = 21780522308. Its totient is φ = 21780522306.

The previous prime is 21780522259. The next prime is 21780522347. The reversal of 21780522307 is 70322508712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21780522307 is a prime.

It is not a weakly prime, because it can be changed into another prime (21780522347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10890261153 + 10890261154.

It is an arithmetic number, because the mean of its divisors is an integer number (10890261154).

Almost surely, 2^21780522307 is an apocalyptic number.

21780522307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21780522307 is an equidigital number, since it uses as much as digits as its factorization.

21780522307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47040, while the sum is 37.

The spelling of 21780522307 in words is "twenty-one billion, seven hundred eighty million, five hundred twenty-two thousand, three hundred seven".