621206641 has 4 divisors (see below), whose sum is σ = 677679984. Its totient is φ = 564733300.

The previous prime is 621206629. The next prime is 621206683. The reversal of 621206641 is 146602126.

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 621206641 - 2¹³ = 621198449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (624206641) 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, 28236655 + ... + 28236676.

It is an arithmetic number, because the mean of its divisors is an integer number (169419996).

Almost surely, 2^621206641 is an apocalyptic number.

It is an amenable number.

621206641 is a deficient number, since it is larger than the sum of its proper divisors (56473343).

621206641 is a wasteful number, since it uses less digits than its factorization.

621206641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56473342.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 621206641 is about 24924.0173527463. The cubic root of 621206641 is about 853.2547146232.

Adding to 621206641 its reverse (146602126), we get a palindrome (767808767).

The spelling of 621206641 in words is "six hundred twenty-one million, two hundred six thousand, six hundred forty-one".