69138991 has 2 divisors, whose sum is σ = 69138992. Its totient is φ = 69138990.

The previous prime is 69138947. The next prime is 69139001. The reversal of 69138991 is 19983196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 69138991 - 2⁹ = 69138479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (69138191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34569495 + 34569496.

It is an arithmetic number, because the mean of its divisors is an integer number (34569496).

Almost surely, 2^69138991 is an apocalyptic number.

69138991 is a deficient number, since it is larger than the sum of its proper divisors (1).

69138991 is an equidigital number, since it uses as much as digits as its factorization.

69138991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 46.

The square root of 69138991 is about 8314.9859290320. The cubic root of 69138991 is about 410.4318095861.

The spelling of 69138991 in words is "sixty-nine million, one hundred thirty-eight thousand, nine hundred ninety-one".