621643361 has 2 divisors, whose sum is σ = 621643362. Its totient is φ = 621643360.

The previous prime is 621643331. The next prime is 621643427. The reversal of 621643361 is 163346126.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 393784336 + 227859025 = 19844^2 + 15095^2 .

It is a cyclic number.

It is not a de Polignac number, because 621643361 - 2¹⁰ = 621642337 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (621643331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310821680 + 310821681.

It is an arithmetic number, because the mean of its divisors is an integer number (310821681).

Almost surely, 2^621643361 is an apocalyptic number.

It is an amenable number.

621643361 is a deficient number, since it is larger than the sum of its proper divisors (1).

621643361 is an equidigital number, since it uses as much as digits as its factorization.

621643361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 32.

The square root of 621643361 is about 24932.7768409377. The cubic root of 621643361 is about 853.4546191776.

Adding to 621643361 its reverse (163346126), we get a palindrome (784989487).

The spelling of 621643361 in words is "six hundred twenty-one million, six hundred forty-three thousand, three hundred sixty-one".