7971945 has 16 divisors (see below), whose sum is σ = 12888960. Its totient is φ = 4207104.

The previous prime is 7971919. The next prime is 7971959. The reversal of 7971945 is 5491797.

It is a happy number.

It is not a de Polignac number, because 7971945 - 2⁵ = 7971913 is a prime.

It is a Curzon number.

7971945 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7971897 and 7971906.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1285 + ... + 4194.

It is an arithmetic number, because the mean of its divisors is an integer number (805560).

Almost surely, 2^7971945 is an apocalyptic number.

It is an amenable number.

7971945 is a deficient number, since it is larger than the sum of its proper divisors (4917015).

7971945 is a wasteful number, since it uses less digits than its factorization.

7971945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5584.

The product of its digits is 79380, while the sum is 42.

The square root of 7971945 is about 2823.4632988583. The cubic root of 7971945 is about 199.7659345069.

The spelling of 7971945 in words is "seven million, nine hundred seventy-one thousand, nine hundred forty-five".