138502261 has 2 divisors, whose sum is σ = 138502262. Its totient is φ = 138502260.

The previous prime is 138502219. The next prime is 138502291. The reversal of 138502261 is 162205831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89586225 + 48916036 = 9465^2 + 6994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138502261 is a prime.

It is a super-2 number, since 2×138502261² = 38365752604224242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138502201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69251130 + 69251131.

It is an arithmetic number, because the mean of its divisors is an integer number (69251131).

Almost surely, 2^138502261 is an apocalyptic number.

It is an amenable number.

138502261 is a deficient number, since it is larger than the sum of its proper divisors (1).

138502261 is an equidigital number, since it uses as much as digits as its factorization.

138502261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 138502261 is about 11768.6983562329. The cubic root of 138502261 is about 517.3911006435.

The spelling of 138502261 in words is "one hundred thirty-eight million, five hundred two thousand, two hundred sixty-one".