138977961 has 8 divisors (see below), whose sum is σ = 185361120. Its totient is φ = 92623392.

The previous prime is 138977959. The next prime is 138977977. The reversal of 138977961 is 169779831.

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

It is not a de Polignac number, because 138977961 - 2¹ = 138977959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138977921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10246 + ... + 19568.

It is an arithmetic number, because the mean of its divisors is an integer number (23170140).

Almost surely, 2^138977961 is an apocalyptic number.

It is an amenable number.

138977961 is a deficient number, since it is larger than the sum of its proper divisors (46383159).

138977961 is an equidigital number, since it uses as much as digits as its factorization.

138977961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14295.

The product of its digits is 571536, while the sum is 51.

The square root of 138977961 is about 11788.8914237090. The cubic root of 138977961 is about 517.9827677715.

The spelling of 138977961 in words is "one hundred thirty-eight million, nine hundred seventy-seven thousand, nine hundred sixty-one".