626721 has 4 divisors (see below), whose sum is σ = 835632. Its totient is φ = 417812.

The previous prime is 626713. The next prime is 626723. The reversal of 626721 is 127626.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 626721 - 2³ = 626713 is a prime.

It is a D-number.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 626691 and 626700.

It is not an unprimeable number, because it can be changed into a prime (626723) 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, 104451 + ... + 104456.

It is an arithmetic number, because the mean of its divisors is an integer number (208908).

2⁶²⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

626721 is a deficient number, since it is larger than the sum of its proper divisors (208911).

626721 is a wasteful number, since it uses less digits than its factorization.

626721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208910.

The product of its digits is 1008, while the sum is 24.

The square root of 626721 is about 791.6571227495. The cubic root of 626721 is about 85.5772019090.

The spelling of 626721 in words is "six hundred twenty-six thousand, seven hundred twenty-one".