621612491 has 2 divisors, whose sum is σ = 621612492. Its totient is φ = 621612490.

The previous prime is 621612443. The next prime is 621612529. The reversal of 621612491 is 194216126.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 621612491 - 2⁶ = 621612427 is a prime.

It is not a weakly prime, because it can be changed into another prime (621612091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310806245 + 310806246.

It is an arithmetic number, because the mean of its divisors is an integer number (310806246).

Almost surely, 2^621612491 is an apocalyptic number.

621612491 is a deficient number, since it is larger than the sum of its proper divisors (1).

621612491 is an equidigital number, since it uses as much as digits as its factorization.

621612491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 621612491 is about 24932.1577686329. The cubic root of 621612491 is about 853.4404917953.

The spelling of 621612491 in words is "six hundred twenty-one million, six hundred twelve thousand, four hundred ninety-one".