400377221 has 4 divisors (see below), whose sum is σ = 406940844. Its totient is φ = 393813600.

The previous prime is 400377209. The next prime is 400377233. The reversal of 400377221 is 122773004.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (400377209) and next prime (400377233).

It can be written as a sum of positive squares in 2 ways, for example, as 115240225 + 285136996 = 10735^2 + 16886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400377221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400377281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3281720 + ... + 3281841.

It is an arithmetic number, because the mean of its divisors is an integer number (101735211).

Almost surely, 2^400377221 is an apocalyptic number.

It is an amenable number.

400377221 is a deficient number, since it is larger than the sum of its proper divisors (6563623).

400377221 is an equidigital number, since it uses as much as digits as its factorization.

400377221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6563622.

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 400377221 is about 20009.4283026777. The cubic root of 400377221 is about 737.0378426319.

The spelling of 400377221 in words is "four hundred million, three hundred seventy-seven thousand, two hundred twenty-one".