397639 has 8 divisors (see below), whose sum is σ = 445968. Its totient is φ = 351360.

The previous prime is 397633. The next prime is 397643. The reversal of 397639 is 936793.

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 397639 - 2⁹ = 397127 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a d-powerful number, because it can be written as 3² + 9 + 6⁷ + 7⁶ + 3³ + 9 .

It is a Duffinian number.

It is a nialpdrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 397598 and 397607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397633) 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, 82 + ... + 895.

It is an arithmetic number, because the mean of its divisors is an integer number (55746).

2³⁹⁷⁶³⁹ is an apocalyptic number.

397639 is a deficient number, since it is larger than the sum of its proper divisors (48329).

397639 is a wasteful number, since it uses less digits than its factorization.

397639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025.

The product of its digits is 30618, while the sum is 37.

The square root of 397639 is about 630.5862351812. The cubic root of 397639 is about 73.5353771725.

The spelling of 397639 in words is "three hundred ninety-seven thousand, six hundred thirty-nine".