400672639 has 2 divisors, whose sum is σ = 400672640. Its totient is φ = 400672638.

The previous prime is 400672637. The next prime is 400672661. The reversal of 400672639 is 936276004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400672639 - 2¹ = 400672637 is a prime.

Together with 400672637, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 400672598 and 400672607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400672637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200336319 + 200336320.

It is an arithmetic number, because the mean of its divisors is an integer number (200336320).

Almost surely, 2^400672639 is an apocalyptic number.

400672639 is a deficient number, since it is larger than the sum of its proper divisors (1).

400672639 is an equidigital number, since it uses as much as digits as its factorization.

400672639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 37.

The square root of 400672639 is about 20016.8089115123. The cubic root of 400672639 is about 737.2190723192.

The spelling of 400672639 in words is "four hundred million, six hundred seventy-two thousand, six hundred thirty-nine".