396107981 has 4 divisors (see below), whose sum is σ = 396301500. Its totient is φ = 395914464.

The previous prime is 396107947. The next prime is 396107993. The reversal of 396107981 is 189701693.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 189701693 = 12113 ⋅15661.

It can be written as a sum of positive squares in 2 ways, for example, as 30151081 + 365956900 = 5491^2 + 19130^2 .

It is a cyclic number.

It is not a de Polignac number, because 396107981 - 2⁶ = 396107917 is a prime.

It is a super-2 number, since 2×396107981² = 313803065223792722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396107281) 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, 93656 + ... + 97793.

It is an arithmetic number, because the mean of its divisors is an integer number (99075375).

Almost surely, 2^396107981 is an apocalyptic number.

It is an amenable number.

396107981 is a deficient number, since it is larger than the sum of its proper divisors (193519).

396107981 is a wasteful number, since it uses less digits than its factorization.

396107981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193518.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 396107981 is about 19902.4616819126. The cubic root of 396107981 is about 734.4087867624.

The spelling of 396107981 in words is "three hundred ninety-six million, one hundred seven thousand, nine hundred eighty-one".