120631981 has 2 divisors, whose sum is σ = 120631982. Its totient is φ = 120631980.

The previous prime is 120631919. The next prime is 120631997. The reversal of 120631981 is 189136021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86304100 + 34327881 = 9290^2 + 5859^2 .

It is an emirp because it is prime and its reverse (189136021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 120631981 - 2¹⁷ = 120500909 is a prime.

It is a super-2 number, since 2×120631981² = 29104149679968722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (120631081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60315990 + 60315991.

It is an arithmetic number, because the mean of its divisors is an integer number (60315991).

Almost surely, 2^120631981 is an apocalyptic number.

It is an amenable number.

120631981 is a deficient number, since it is larger than the sum of its proper divisors (1).

120631981 is an equidigital number, since it uses as much as digits as its factorization.

120631981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 120631981 is about 10983.2591246861. The cubic root of 120631981 is about 494.1067876579.

The spelling of 120631981 in words is "one hundred twenty million, six hundred thirty-one thousand, nine hundred eighty-one".