396128881 has 4 divisors (see below), whose sum is σ = 408907264. Its totient is φ = 383350500.

The previous prime is 396128869. The next prime is 396128897. The reversal of 396128881 is 188821693.

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, and also an emirpimes, since its reverse is a distinct semiprime: 188821693 = 37 ⋅5103289.

It is a cyclic number.

It is not a de Polignac number, because 396128881 - 2¹¹ = 396126833 is a prime.

It is a super-2 number, since 2×396128881² = 313836180724624322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (396128851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6389145 + ... + 6389206.

It is an arithmetic number, because the mean of its divisors is an integer number (102226816).

Almost surely, 2^396128881 is an apocalyptic number.

396128881 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

396128881 is a deficient number, since it is larger than the sum of its proper divisors (12778383).

396128881 is a wasteful number, since it uses less digits than its factorization.

396128881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12778382.

The product of its digits is 165888, while the sum is 46.

The square root of 396128881 is about 19902.9867356636. The cubic root of 396128881 is about 734.4217031677.

The spelling of 396128881 in words is "three hundred ninety-six million, one hundred twenty-eight thousand, eight hundred eighty-one".