3720991 has 4 divisors (see below), whose sum is σ = 3736800. Its totient is φ = 3705184.

The previous prime is 3720989. The next prime is 3721027. The reversal of 3720991 is 1990273.

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 3720991 - 2¹ = 3720989 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3720911) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 7546 + ... + 8023.

It is an arithmetic number, because the mean of its divisors is an integer number (934200).

Almost surely, 2^3720991 is an apocalyptic number.

3720991 is a deficient number, since it is larger than the sum of its proper divisors (15809).

3720991 is a wasteful number, since it uses less digits than its factorization.

3720991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15808.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 3720991 is about 1928.9870398735. The cubic root of 3720991 is about 154.9599757914.

It can be divided in two parts, 372099 and 1, that added together give a square (372100 = 610²).

The spelling of 3720991 in words is "three million, seven hundred twenty thousand, nine hundred ninety-one".