81479202137 has 2 divisors, whose sum is σ = 81479202138. Its totient is φ = 81479202136.

The previous prime is 81479202127. The next prime is 81479202143. The reversal of 81479202137 is 73120297418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60191224921 + 21287977216 = 245339^2 + 145904^2 .

It is a cyclic number.

It is not a de Polignac number, because 81479202137 - 2¹⁶ = 81479136601 is a prime.

It is not a weakly prime, because it can be changed into another prime (81479202127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40739601068 + 40739601069.

It is an arithmetic number, because the mean of its divisors is an integer number (40739601069).

Almost surely, 2^81479202137 is an apocalyptic number.

It is an amenable number.

81479202137 is a deficient number, since it is larger than the sum of its proper divisors (1).

81479202137 is an equidigital number, since it uses as much as digits as its factorization.

81479202137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344, while the sum is 44.

The spelling of 81479202137 in words is "eighty-one billion, four hundred seventy-nine million, two hundred two thousand, one hundred thirty-seven".