3651121891 has 8 divisors (see below), whose sum is σ = 3673425600. Its totient is φ = 3628839720.

The previous prime is 3651121801. The next prime is 3651121933. The reversal of 3651121891 is 1981211563.

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

It is a cyclic number.

It is not a de Polignac number, because 3651121891 - 2²⁷ = 3516904163 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3651121891.

It is not an unprimeable number, because it can be changed into a prime (3651121801) 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, 449020 + ... + 457078.

It is an arithmetic number, because the mean of its divisors is an integer number (459178200).

Almost surely, 2^3651121891 is an apocalyptic number.

3651121891 is a deficient number, since it is larger than the sum of its proper divisors (22303709).

3651121891 is a wasteful number, since it uses less digits than its factorization.

3651121891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10769.

The product of its digits is 12960, while the sum is 37.

The square root of 3651121891 is about 60424.5139905982. The cubic root of 3651121891 is about 1539.8394574589.

The spelling of 3651121891 in words is "three billion, six hundred fifty-one million, one hundred twenty-one thousand, eight hundred ninety-one".