3921690 has 32 divisors (see below), whose sum is σ = 9570816. Its totient is φ = 1028160.

The previous prime is 3921689. The next prime is 3921719. The reversal of 3921690 is 961293.

It is a super-2 number, since 2×3921690² = 30759304912200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 759 + ... + 2901.

It is an arithmetic number, because the mean of its divisors is an integer number (299088).

Almost surely, 2^3921690 is an apocalyptic number.

3921690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 3921690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4785408).

3921690 is an abundant number, since it is smaller than the sum of its proper divisors (5649126).

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

3921690 is a wasteful number, since it uses less digits than its factorization.

3921690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2214.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 3921690 is about 1980.3257307827. The cubic root of 3921690 is about 157.6973590413.

The spelling of 3921690 in words is "three million, nine hundred twenty-one thousand, six hundred ninety".