3951284721 has 16 divisors (see below), whose sum is σ = 5579933184. Its totient is φ = 2478504704.

The previous prime is 3951284683. The next prime is 3951284737. The reversal of 3951284721 is 1274821593.

It is a cyclic number.

It is not a de Polignac number, because 3951284721 - 2⁶ = 3951284657 is a prime.

It is a super-2 number, since 2×3951284721² = 31225301892816095682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3951284761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201091 + ... + 219863.

It is an arithmetic number, because the mean of its divisors is an integer number (348745824).

Almost surely, 2^3951284721 is an apocalyptic number.

It is an amenable number.

3951284721 is a deficient number, since it is larger than the sum of its proper divisors (1628648463).

3951284721 is a wasteful number, since it uses less digits than its factorization.

3951284721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22920.

The product of its digits is 120960, while the sum is 42.

The square root of 3951284721 is about 62859.2453104553. The cubic root of 3951284721 is about 1580.9304887382.

The spelling of 3951284721 in words is "three billion, nine hundred fifty-one million, two hundred eighty-four thousand, seven hundred twenty-one".