6221561999 has 8 divisors (see below), whose sum is σ = 6293738880. Its totient is φ = 6149435776.

The previous prime is 6221561953. The next prime is 6221562013. The reversal of 6221561999 is 9991651226.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6221561999 - 2²⁰ = 6220513423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6221561299) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 270827 + ... + 292899.

It is an arithmetic number, because the mean of its divisors is an integer number (786717360).

Almost surely, 2^6221561999 is an apocalyptic number.

6221561999 is a deficient number, since it is larger than the sum of its proper divisors (72176881).

6221561999 is a wasteful number, since it uses less digits than its factorization.

6221561999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25329.

The product of its digits is 524880, while the sum is 50.

The square root of 6221561999 is about 78876.8787351528. The cubic root of 6221561999 is about 1839.2177281741.

The spelling of 6221561999 in words is "six billion, two hundred twenty-one million, five hundred sixty-one thousand, nine hundred ninety-nine".