621161251 has 2 divisors, whose sum is σ = 621161252. Its totient is φ = 621161250.

The previous prime is 621161227. The next prime is 621161267. The reversal of 621161251 is 152161126.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621161251 is a prime.

It is not a weakly prime, because it can be changed into another prime (621161951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310580625 + 310580626.

It is an arithmetic number, because the mean of its divisors is an integer number (310580626).

Almost surely, 2^621161251 is an apocalyptic number.

621161251 is a deficient number, since it is larger than the sum of its proper divisors (1).

621161251 is an equidigital number, since it uses as much as digits as its factorization.

621161251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 621161251 is about 24923.1067686194. The cubic root of 621161251 is about 853.2339323948.

The spelling of 621161251 in words is "six hundred twenty-one million, one hundred sixty-one thousand, two hundred fifty-one".