1377997731 has 48 divisors (see below), whose sum is σ = 2251253760. Its totient is φ = 832431600.

The previous prime is 1377997723. The next prime is 1377997739.

1377997731 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1377997723) and next prime (1377997739).

It is not a de Polignac number, because 1377997731 - 2³ = 1377997723 is a prime.

It is a super-2 number, since 2×1377997731² = 3797755493282296722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1377997739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1512166 + ... + 1513076.

It is an arithmetic number, because the mean of its divisors is an integer number (46901120).

Almost surely, 2^1377997731 is an apocalyptic number.

1377997731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1377997731 is a deficient number, since it is larger than the sum of its proper divisors (873256029).

1377997731 is a wasteful number, since it uses less digits than its factorization.

1377997731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1405 (or 1388 counting only the distinct ones).

The product of its digits is 1750329, while the sum is 54.

The square root of 1377997731 is about 37121.3918246609. The cubic root of 1377997731 is about 1112.7975670953.

It can be divided in two parts, 137799 and 7731, that added together give a triangular number (145530 = T₅₃₉).

The spelling of 1377997731 in words is "one billion, three hundred seventy-seven million, nine hundred ninety-seven thousand, seven hundred thirty-one".