3891780 has 48 divisors (see below), whose sum is σ = 12109440. Its totient is φ = 1037664.

The previous prime is 3891779. The next prime is 3891781. The reversal of 3891780 is 871983.

It is an interprime number because it is at equal distance from previous prime (3891779) and next prime (3891781).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (3891781) 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, 3064 + ... + 4143.

It is an arithmetic number, because the mean of its divisors is an integer number (252280).

Almost surely, 2^3891780 is an apocalyptic number.

3891780 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3891780 is an abundant number, since it is smaller than the sum of its proper divisors (8217660).

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

3891780 is a wasteful number, since it uses less digits than its factorization.

3891780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7225 (or 7217 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 3891780 is about 1972.7594886351. The cubic root of 3891780 is about 157.2954260074.

The spelling of 3891780 in words is "three million, eight hundred ninety-one thousand, seven hundred eighty".