138677986 has 4 divisors (see below), whose sum is σ = 208016982. Its totient is φ = 69338992.

The previous prime is 138677951. The next prime is 138677989. The reversal of 138677986 is 689776831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 69472225 + 69205761 = 8335^2 + 8319^2 .

It is not an unprimeable number, because it can be changed into a prime (138677989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34669495 + ... + 34669498.

Almost surely, 2^138677986 is an apocalyptic number.

138677986 is a deficient number, since it is larger than the sum of its proper divisors (69338996).

138677986 is an equidigital number, since it uses as much as digits as its factorization.

138677986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69338995.

The product of its digits is 3048192, while the sum is 55.

The square root of 138677986 is about 11776.1617685900. The cubic root of 138677986 is about 517.6098218074.

The spelling of 138677986 in words is "one hundred thirty-eight million, six hundred seventy-seven thousand, nine hundred eighty-six".