404630981 has 2 divisors, whose sum is σ = 404630982. Its totient is φ = 404630980.

The previous prime is 404630977. The next prime is 404630987. The reversal of 404630981 is 189036404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 390418081 + 14212900 = 19759^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 404630981 - 2² = 404630977 is a prime.

It is a super-2 number, since 2×404630981² = 327452461570044722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404630987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202315490 + 202315491.

It is an arithmetic number, because the mean of its divisors is an integer number (202315491).

Almost surely, 2^404630981 is an apocalyptic number.

It is an amenable number.

404630981 is a deficient number, since it is larger than the sum of its proper divisors (1).

404630981 is an equidigital number, since it uses as much as digits as its factorization.

404630981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 404630981 is about 20115.4413573255. The cubic root of 404630981 is about 739.6388431233.

The spelling of 404630981 in words is "four hundred four million, six hundred thirty thousand, nine hundred eighty-one".