138731761 has 8 divisors (see below), whose sum is σ = 160461504. Its totient is φ = 117479760.

The previous prime is 138731729. The next prime is 138731767. The reversal of 138731761 is 167137831.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138731761 - 2⁵ = 138731729 is a prime.

It is a super-2 number, since 2×138731761² = 38493003020322242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138731761.

It is not an unprimeable number, because it can be changed into a prime (138731767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118810 + ... + 119971.

It is an arithmetic number, because the mean of its divisors is an integer number (20057688).

Almost surely, 2^138731761 is an apocalyptic number.

It is an amenable number.

138731761 is a deficient number, since it is larger than the sum of its proper divisors (21729743).

138731761 is an equidigital number, since it uses as much as digits as its factorization.

138731761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238871.

The product of its digits is 21168, while the sum is 37.

The square root of 138731761 is about 11778.4447615124. Note that the first 3 decimals coincide. The cubic root of 138731761 is about 517.6767174793.

The spelling of 138731761 in words is "one hundred thirty-eight million, seven hundred thirty-one thousand, seven hundred sixty-one".