8139997 has 2 divisors, whose sum is σ = 8139998. Its totient is φ = 8139996.

The previous prime is 8139983. The next prime is 8140001. The reversal of 8139997 is 7999318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6320196 + 1819801 = 2514^2 + 1349^2 .

It is a cyclic number.

It is not a de Polignac number, because 8139997 - 2⁷ = 8139869 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8139917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4069998 + 4069999.

It is an arithmetic number, because the mean of its divisors is an integer number (4069999).

Almost surely, 2^8139997 is an apocalyptic number.

It is an amenable number.

8139997 is a deficient number, since it is larger than the sum of its proper divisors (1).

8139997 is an equidigital number, since it uses as much as digits as its factorization.

8139997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 46.

The square root of 8139997 is about 2853.0679977876. The cubic root of 8139997 is about 201.1599018016.

The spelling of 8139997 in words is "eight million, one hundred thirty-nine thousand, nine hundred ninety-seven".