7920981 has 6 divisors (see below), whose sum is σ = 11441430. Its totient is φ = 5280648.

The previous prime is 7920959. The next prime is 7921003. The reversal of 7920981 is 1890297.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (7920959) and next prime (7921003).

It can be written as a sum of positive squares in only one way, i.e., 6502500 + 1418481 = 2550^2 + 1191^2 .

It is not a de Polignac number, because 7920981 - 2⁵ = 7920949 is a prime.

It is a super-2 number, since 2×7920981² = 125483880004722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7920481) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 440046 + ... + 440063.

It is an arithmetic number, because the mean of its divisors is an integer number (1906905).

Almost surely, 2^7920981 is an apocalyptic number.

It is an amenable number.

7920981 is a deficient number, since it is larger than the sum of its proper divisors (3520449).

7920981 is a wasteful number, since it uses less digits than its factorization.

7920981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880115 (or 880112 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 7920981 is about 2814.4237420829. The cubic root of 7920981 is about 199.3393283010.

The spelling of 7920981 in words is "seven million, nine hundred twenty thousand, nine hundred eighty-one".