621397 has 4 divisors (see below), whose sum is σ = 710176. Its totient is φ = 532620.

The previous prime is 621389. The next prime is 621419. The reversal of 621397 is 793126.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 793126 = 2 ⋅396563.

It is a cyclic number.

It is not a de Polignac number, because 621397 - 2³ = 621389 is a prime.

It is a super-2 number, since 2×621397² = 772268463218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621317) 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, 44379 + ... + 44392.

It is an arithmetic number, because the mean of its divisors is an integer number (177544).

2⁶²¹³⁹⁷ is an apocalyptic number.

It is an amenable number.

621397 is a deficient number, since it is larger than the sum of its proper divisors (88779).

621397 is an equidigital number, since it uses as much as digits as its factorization.

621397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88778.

The product of its digits is 2268, while the sum is 28.

The square root of 621397 is about 788.2873841436. The cubic root of 621397 is about 85.3341861216.

The spelling of 621397 in words is "six hundred twenty-one thousand, three hundred ninety-seven".