397661155 has 4 divisors (see below), whose sum is σ = 477193392. Its totient is φ = 318128920.

The previous prime is 397661153. The next prime is 397661189. The reversal of 397661155 is 551166793.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 551166793 = 787 ⋅700339.

It is not a de Polignac number, because 397661155 - 2¹ = 397661153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397661153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39766111 + ... + 39766120.

It is an arithmetic number, because the mean of its divisors is an integer number (119298348).

Almost surely, 2^397661155 is an apocalyptic number.

397661155 is a deficient number, since it is larger than the sum of its proper divisors (79532237).

397661155 is an equidigital number, since it uses as much as digits as its factorization.

397661155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79532236.

The product of its digits is 170100, while the sum is 43.

The square root of 397661155 is about 19941.4431523899. The cubic root of 397661155 is about 735.3674285512.

The spelling of 397661155 in words is "three hundred ninety-seven million, six hundred sixty-one thousand, one hundred fifty-five".