138662405 has 24 divisors (see below), whose sum is σ = 196238232. Its totient is φ = 93768192.

The previous prime is 138662393. The next prime is 138662417. The reversal of 138662405 is 504266831.

It is an interprime number because it is at equal distance from previous prime (138662393) and next prime (138662417).

It can be written as a sum of positive squares in 4 ways, for example, as 59505796 + 79156609 = 7714^2 + 8897^2 .

It is not a de Polignac number, because 138662405 - 2⁴ = 138662389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14009 + ... + 21761.

It is an arithmetic number, because the mean of its divisors is an integer number (8176593).

Almost surely, 2^138662405 is an apocalyptic number.

It is an amenable number.

138662405 is a deficient number, since it is larger than the sum of its proper divisors (57575827).

138662405 is an equidigital number, since it uses as much as digits as its factorization.

138662405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7845 (or 7838 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 138662405 is about 11775.5002016899. The cubic root of 138662405 is about 517.5904359363.

It can be divided in two parts, 13866240 and 5, that multiplied together give a triangular number (69331200 = T₁₁₇₇₅).

The spelling of 138662405 in words is "one hundred thirty-eight million, six hundred sixty-two thousand, four hundred five".