1397772381 has 4 divisors (see below), whose sum is σ = 1863696512. Its totient is φ = 931848252.

The previous prime is 1397772329. The next prime is 1397772401. The reversal of 1397772381 is 1832777931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1397772381 - 2⁷ = 1397772253 is a prime.

It is a super-2 number, since 2×1397772381² = 3907535258172818322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1397772381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397772281) 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 3 ways as a sum of consecutive naturals, for example, 232962061 + ... + 232962066.

It is an arithmetic number, because the mean of its divisors is an integer number (465924128).

Almost surely, 2^1397772381 is an apocalyptic number.

It is an amenable number.

1397772381 is a deficient number, since it is larger than the sum of its proper divisors (465924131).

1397772381 is an equidigital number, since it uses as much as digits as its factorization.

1397772381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465924130.

The product of its digits is 444528, while the sum is 48.

The square root of 1397772381 is about 37386.7942059760. The cubic root of 1397772381 is about 1118.0952907387.

The spelling of 1397772381 in words is "one billion, three hundred ninety-seven million, seven hundred seventy-two thousand, three hundred eighty-one".