3891651 has 4 divisors (see below), whose sum is σ = 5188872. Its totient is φ = 2594432.

The previous prime is 3891593. The next prime is 3891659. The reversal of 3891651 is 1561983.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3891651 - 2¹⁹ = 3367363 is a prime.

It is a D-number.

3891651 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3891659) 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, 648606 + ... + 648611.

It is an arithmetic number, because the mean of its divisors is an integer number (1297218).

Almost surely, 2^3891651 is an apocalyptic number.

3891651 is a deficient number, since it is larger than the sum of its proper divisors (1297221).

3891651 is a wasteful number, since it uses less digits than its factorization.

3891651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297220.

The product of its digits is 6480, while the sum is 33.

The square root of 3891651 is about 1972.7267930456. The cubic root of 3891651 is about 157.2936880423.

The spelling of 3891651 in words is "three million, eight hundred ninety-one thousand, six hundred fifty-one".