3651991272 has 120 divisors (see below), whose sum is σ = 10866611910. Its totient is φ = 1145664000.

The previous prime is 3651991271. The next prime is 3651991297. The reversal of 3651991272 is 2721991563.

It is a happy number.

3651991272 is a `hidden beast` number, since 3 + 6 + 519 + 9 + 127 + 2 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 3629580516 + 22410756 = 60246^2 + 4734^2 .

It is not an unprimeable number, because it can be changed into a prime (3651991271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 177522 + ... + 197022.

Almost surely, 2^3651991272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3651991272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5433305955).

3651991272 is an abundant number, since it is smaller than the sum of its proper divisors (7214620638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3651991272 is a wasteful number, since it uses less digits than its factorization.

3651991272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19553 (or 19523 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 3651991272 is about 60431.7075052493. The cubic root of 3651991272 is about 1539.9616665558.

The spelling of 3651991272 in words is "three billion, six hundred fifty-one million, nine hundred ninety-one thousand, two hundred seventy-two".