3951613221 has 4 divisors (see below), whose sum is σ = 5268817632. Its totient is φ = 2634408812.

The previous prime is 3951613213. The next prime is 3951613241. The reversal of 3951613221 is 1223161593.

3951613221 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3951613221 - 2³ = 3951613213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3951613241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 658602201 + ... + 658602206.

It is an arithmetic number, because the mean of its divisors is an integer number (1317204408).

Almost surely, 2^3951613221 is an apocalyptic number.

It is an amenable number.

3951613221 is a deficient number, since it is larger than the sum of its proper divisors (1317204411).

3951613221 is a wasteful number, since it uses less digits than its factorization.

3951613221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317204410.

The product of its digits is 9720, while the sum is 33.

The square root of 3951613221 is about 62861.8582369309. The cubic root of 3951613221 is about 1580.9742990692.

The spelling of 3951613221 in words is "three billion, nine hundred fifty-one million, six hundred thirteen thousand, two hundred twenty-one".