621311645 has 8 divisors (see below), whose sum is σ = 746064600. Its totient is φ = 496722240.

The previous prime is 621311623. The next prime is 621311651. The reversal of 621311645 is 546113126.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 33200644 + 588111001 = 5762^2 + 24251^2 .

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

It is not a de Polignac number, because 621311645 - 2⁸ = 621311389 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32366 + ... + 47855.

It is an arithmetic number, because the mean of its divisors is an integer number (93258075).

Almost surely, 2^621311645 is an apocalyptic number.

It is an amenable number.

621311645 is a deficient number, since it is larger than the sum of its proper divisors (124752955).

621311645 is a wasteful number, since it uses less digits than its factorization.

621311645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81775.

The product of its digits is 4320, while the sum is 29.

The square root of 621311645 is about 24926.1237459818. The cubic root of 621311645 is about 853.3027877894.

The spelling of 621311645 in words is "six hundred twenty-one million, three hundred eleven thousand, six hundred forty-five".