7971990 has 32 divisors (see below), whose sum is σ = 20605536. Its totient is φ = 1962240.

The previous prime is 7971973. The next prime is 7972009. The reversal of 7971990 is 991797.

It is a nialpdrome in base 15.

It is a congruent number.

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, 9831 + ... + 10610.

It is an arithmetic number, because the mean of its divisors is an integer number (643923).

Almost surely, 2^7971990 is an apocalyptic number.

7971990 is an abundant number, since it is smaller than the sum of its proper divisors (12633546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7971990 is a wasteful number, since it uses less digits than its factorization.

7971990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20464.

The product of its (nonzero) digits is 35721, while the sum is 42.

The square root of 7971990 is about 2823.4712677837. The cubic root of 7971990 is about 199.7663103855.

The spelling of 7971990 in words is "seven million, nine hundred seventy-one thousand, nine hundred ninety".