7999940 has 48 divisors (see below), whose sum is σ = 18733680. Its totient is φ = 2849280.

The previous prime is 7999921. The next prime is 7999963. The reversal of 7999940 is 499997.

It can be written as a sum of positive squares in 8 ways, for example, as 238144 + 7761796 = 488^2 + 2786^2 .

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, 7010 + ... + 8070.

It is an arithmetic number, because the mean of its divisors is an integer number (390285).

Almost surely, 2^7999940 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7999940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9366840).

7999940 is an abundant number, since it is smaller than the sum of its proper divisors (10733740).

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

7999940 is a wasteful number, since it uses less digits than its factorization.

7999940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112 (or 1110 counting only the distinct ones).

The product of its (nonzero) digits is 183708, while the sum is 47.

The square root of 7999940 is about 2828.4165181246. The cubic root of 7999940 is about 199.9994999987. Note that the first 3 decimals are identical.

The spelling of 7999940 in words is "seven million, nine hundred ninety-nine thousand, nine hundred forty".