21167255939 has 2 divisors, whose sum is σ = 21167255940. Its totient is φ = 21167255938.

The previous prime is 21167255903. The next prime is 21167255959. The reversal of 21167255939 is 93955276112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21167255939 - 2¹² = 21167251843 is a prime.

It is not a weakly prime, because it can be changed into another prime (21167255959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583627969 + 10583627970.

It is an arithmetic number, because the mean of its divisors is an integer number (10583627970).

Almost surely, 2^21167255939 is an apocalyptic number.

21167255939 is a deficient number, since it is larger than the sum of its proper divisors (1).

21167255939 is an equidigital number, since it uses as much as digits as its factorization.

21167255939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1020600, while the sum is 50.

The spelling of 21167255939 in words is "twenty-one billion, one hundred sixty-seven million, two hundred fifty-five thousand, nine hundred thirty-nine".