1621847221 has 8 divisors (see below), whose sum is σ = 1633452480. Its totient is φ = 1610270592.

The previous prime is 1621847207. The next prime is 1621847261. The reversal of 1621847221 is 1227481261.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621847221 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 (1621847261) 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, 113736 + ... + 127198.

It is an arithmetic number, because the mean of its divisors is an integer number (204181560).

Almost surely, 2^1621847221 is an apocalyptic number.

It is an amenable number.

1621847221 is a deficient number, since it is larger than the sum of its proper divisors (11605259).

1621847221 is a wasteful number, since it uses less digits than its factorization.

1621847221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14315.

The product of its digits is 10752, while the sum is 34.

The square root of 1621847221 is about 40272.1643446190. The cubic root of 1621847221 is about 1174.9065194380.

The spelling of 1621847221 in words is "one billion, six hundred twenty-one million, eight hundred forty-seven thousand, two hundred twenty-one".