621251669 has 4 divisors (see below), whose sum is σ = 625208844. Its totient is φ = 617294496.

The previous prime is 621251663. The next prime is 621251693. The reversal of 621251669 is 966152126.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 414611044 + 206640625 = 20362^2 + 14375^2 .

It is a cyclic number.

It is not a de Polignac number, because 621251669 - 2²⁰ = 620203093 is a prime.

It is a super-2 number, since 2×621251669² = 771907272470571122, 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 (621251663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1978352 + ... + 1978665.

It is an arithmetic number, because the mean of its divisors is an integer number (156302211).

Almost surely, 2^621251669 is an apocalyptic number.

It is an amenable number.

621251669 is a deficient number, since it is larger than the sum of its proper divisors (3957175).

621251669 is a wasteful number, since it uses less digits than its factorization.

621251669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3957174.

The product of its digits is 38880, while the sum is 38.

The square root of 621251669 is about 24924.9206417994. The cubic root of 621251669 is about 853.2753301063.

The spelling of 621251669 in words is "six hundred twenty-one million, two hundred fifty-one thousand, six hundred sixty-nine".