138437977 has 2 divisors, whose sum is σ = 138437978. Its totient is φ = 138437976.

The previous prime is 138437963. The next prime is 138438037. The reversal of 138437977 is 779734831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132342016 + 6095961 = 11504^2 + 2469^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138437977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138437977.

It is not a weakly prime, because it can be changed into another prime (138437917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69218988 + 69218989.

It is an arithmetic number, because the mean of its divisors is an integer number (69218989).

Almost surely, 2^138437977 is an apocalyptic number.

It is an amenable number.

138437977 is a deficient number, since it is larger than the sum of its proper divisors (1).

138437977 is an equidigital number, since it uses as much as digits as its factorization.

138437977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 889056, while the sum is 49.

The square root of 138437977 is about 11765.9668960949. The cubic root of 138437977 is about 517.3110415014.

The spelling of 138437977 in words is "one hundred thirty-eight million, four hundred thirty-seven thousand, nine hundred seventy-seven".