403994989 has 2 divisors, whose sum is σ = 403994990. Its totient is φ = 403994988.

The previous prime is 403994959. The next prime is 403994993. The reversal of 403994989 is 989499304.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 273075625 + 130919364 = 16525^2 + 11442^2 .

It is a cyclic number.

It is not a de Polignac number, because 403994989 - 2²³ = 395606381 is a prime.

It is a super-2 number, since 2×403994989² = 326423902274220242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (403994959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201997494 + 201997495.

It is an arithmetic number, because the mean of its divisors is an integer number (201997495).

Almost surely, 2^403994989 is an apocalyptic number.

It is an amenable number.

403994989 is a deficient number, since it is larger than the sum of its proper divisors (1).

403994989 is an equidigital number, since it uses as much as digits as its factorization.

403994989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2519424, while the sum is 55.

The square root of 403994989 is about 20099.6265885712. The cubic root of 403994989 is about 739.2511227209.

The spelling of 403994989 in words is "four hundred three million, nine hundred ninety-four thousand, nine hundred eighty-nine".