621149755 has 4 divisors (see below), whose sum is σ = 745379712. Its totient is φ = 496919800.

The previous prime is 621149719. The next prime is 621149797. The reversal of 621149755 is 557941126.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 621149755 - 2¹¹ = 621147707 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62114971 + ... + 62114980.

It is an arithmetic number, because the mean of its divisors is an integer number (186344928).

Almost surely, 2^621149755 is an apocalyptic number.

621149755 is a deficient number, since it is larger than the sum of its proper divisors (124229957).

621149755 is a wasteful number, since it uses less digits than its factorization.

621149755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124229956.

The product of its digits is 75600, while the sum is 40.

The square root of 621149755 is about 24922.8761381988. The cubic root of 621149755 is about 853.2286686849.

The spelling of 621149755 in words is "six hundred twenty-one million, one hundred forty-nine thousand, seven hundred fifty-five".