1397638477 has 2 divisors, whose sum is σ = 1397638478. Its totient is φ = 1397638476.

The previous prime is 1397638453. The next prime is 1397638507. The reversal of 1397638477 is 7748367931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1201246281 + 196392196 = 34659^2 + 14014^2 .

It is an emirp because it is prime and its reverse (7748367931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1397638477 - 2⁷ = 1397638349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1397638877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698819238 + 698819239.

It is an arithmetic number, because the mean of its divisors is an integer number (698819239).

Almost surely, 2^1397638477 is an apocalyptic number.

It is an amenable number.

1397638477 is a deficient number, since it is larger than the sum of its proper divisors (1).

1397638477 is an equidigital number, since it uses as much as digits as its factorization.

1397638477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5334336, while the sum is 55.

The square root of 1397638477 is about 37385.0033703355. The cubic root of 1397638477 is about 1118.0595857806.

It can be divided in two parts, 139763 and 8477, that added together give a triangular number (148240 = T₅₄₄).

The spelling of 1397638477 in words is "one billion, three hundred ninety-seven million, six hundred thirty-eight thousand, four hundred seventy-seven".