9157981 has 16 divisors (see below), whose sum is σ = 11320960. Its totient is φ = 7231680.

The previous prime is 9157969. The next prime is 9158003. The reversal of 9157981 is 1897519.

9157981 = T₆₈₅ + T₆₈₆ + ... + T₇₂₁.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 9157981 - 2⁵ = 9157949 is a prime.

It is a super-2 number, since 2×9157981² = 167737231992722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9157901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3991 + ... + 5851.

It is an arithmetic number, because the mean of its divisors is an integer number (707560).

Almost surely, 2^9157981 is an apocalyptic number.

It is an amenable number.

9157981 is a deficient number, since it is larger than the sum of its proper divisors (2162979).

9157981 is a wasteful number, since it uses less digits than its factorization.

9157981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1924.

The product of its digits is 22680, while the sum is 40.

The square root of 9157981 is about 3026.2156235140. The cubic root of 9157981 is about 209.2184174493.

The spelling of 9157981 in words is "nine million, one hundred fifty-seven thousand, nine hundred eighty-one".