400644247 has 2 divisors, whose sum is σ = 400644248. Its totient is φ = 400644246.

The previous prime is 400644109. The next prime is 400644271. The reversal of 400644247 is 742446004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400644247 - 2¹⁵ = 400611479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400641247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200322123 + 200322124.

It is an arithmetic number, because the mean of its divisors is an integer number (200322124).

Almost surely, 2^400644247 is an apocalyptic number.

400644247 is a deficient number, since it is larger than the sum of its proper divisors (1).

400644247 is an equidigital number, since it uses as much as digits as its factorization.

400644247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 31.

The square root of 400644247 is about 20016.0996949955. The cubic root of 400644247 is about 737.2016585868.

The spelling of 400644247 in words is "four hundred million, six hundred forty-four thousand, two hundred forty-seven".