401639 has 8 divisors (see below), whose sum is σ = 463008. Its totient is φ = 341280.

The previous prime is 401629. The next prime is 401651. The reversal of 401639 is 936104.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 401639 - 2¹² = 397543 is a prime.

It is a super-2 number, since 2×401639² = 322627772642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1109 + ... + 1425.

It is an arithmetic number, because the mean of its divisors is an integer number (57876).

2⁴⁰¹⁶³⁹ is an apocalyptic number.

401639 is a deficient number, since it is larger than the sum of its proper divisors (61369).

401639 is a wasteful number, since it uses less digits than its factorization.

401639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 401639 is about 633.7499506903. The cubic root of 401639 is about 73.7811282940.

The spelling of 401639 in words is "four hundred one thousand, six hundred thirty-nine".