400861121 has 2 divisors, whose sum is σ = 400861122. Its totient is φ = 400861120.

The previous prime is 400861117. The next prime is 400861151. The reversal of 400861121 is 121168004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 399000625 + 1860496 = 19975^2 + 1364^2 .

It is a cyclic number.

It is not a de Polignac number, because 400861121 - 2² = 400861117 is a prime.

It is not a weakly prime, because it can be changed into another prime (400861151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200430560 + 200430561.

It is an arithmetic number, because the mean of its divisors is an integer number (200430561).

Almost surely, 2^400861121 is an apocalyptic number.

It is an amenable number.

400861121 is a deficient number, since it is larger than the sum of its proper divisors (1).

400861121 is an equidigital number, since it uses as much as digits as its factorization.

400861121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 400861121 is about 20021.5164510583. The cubic root of 400861121 is about 737.3346535768.

The spelling of 400861121 in words is "four hundred million, eight hundred sixty-one thousand, one hundred twenty-one".