621198809 has 48 divisors (see below), whose sum is σ = 816915456. Its totient is φ = 458740800.

The previous prime is 621198803. The next prime is 621198817. The reversal of 621198809 is 908891126.

It is not a de Polignac number, because 621198809 - 2¹² = 621194713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 621198809.

It is not an unprimeable number, because it can be changed into a prime (621198803) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7484282 + ... + 7484364.

It is an arithmetic number, because the mean of its divisors is an integer number (17019072).

Almost surely, 2^621198809 is an apocalyptic number.

It is an amenable number.

621198809 is a deficient number, since it is larger than the sum of its proper divisors (195716647).

621198809 is a wasteful number, since it uses less digits than its factorization.

621198809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 44.

The square root of 621198809 is about 24923.8602347229. The cubic root of 621198809 is about 853.2511287423.

The spelling of 621198809 in words is "six hundred twenty-one million, one hundred ninety-eight thousand, eight hundred nine".