3991770 has 48 divisors (see below), whose sum is σ = 10993320. Its totient is φ = 1001472.

The previous prime is 3991751. The next prime is 3991807. The reversal of 3991770 is 771993.

It can be written as a sum of positive squares in 4 ways, for example, as 3583449 + 408321 = 1893^2 + 639^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 226 + ... + 2834.

Almost surely, 2^3991770 is an apocalyptic number.

3991770 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 3991770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5496660).

3991770 is an abundant number, since it is smaller than the sum of its proper divisors (7001550).

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

3991770 is a wasteful number, since it uses less digits than its factorization.

3991770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2639 (or 2636 counting only the distinct ones).

The product of its (nonzero) digits is 11907, while the sum is 36.

The square root of 3991770 is about 1997.9414405833. The cubic root of 3991770 is about 158.6311611897.

It can be divided in two parts, 3991 and 770, that added together give a square (4761 = 69²).

The spelling of 3991770 in words is "three million, nine hundred ninety-one thousand, seven hundred seventy".