400412981 has 2 divisors, whose sum is σ = 400412982. Its totient is φ = 400412980.

The previous prime is 400412959. The next prime is 400412983. The reversal of 400412981 is 189214004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 400360081 + 52900 = 20009^2 + 230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400412981 is a prime.

It is a super-2 number, since 2×400412981² = 320661110706612722, which contains 22 as substring.

Together with 400412983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400412983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200206490 + 200206491.

It is an arithmetic number, because the mean of its divisors is an integer number (200206491).

Almost surely, 2^400412981 is an apocalyptic number.

It is an amenable number.

400412981 is a deficient number, since it is larger than the sum of its proper divisors (1).

400412981 is an equidigital number, since it uses as much as digits as its factorization.

400412981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 400412981 is about 20010.3218614794. The cubic root of 400412981 is about 737.0597850130.

Adding to 400412981 its reverse (189214004), we get a palindrome (589626985).

The spelling of 400412981 in words is "four hundred million, four hundred twelve thousand, nine hundred eighty-one".