3721945 has 4 divisors (see below), whose sum is σ = 4466340. Its totient is φ = 2977552.

The previous prime is 3721943. The next prime is 3721957. The reversal of 3721945 is 5491273.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1468944 + 2253001 = 1212^2 + 1501^2 .

It is a cyclic number.

It is not a de Polignac number, because 3721945 - 2¹ = 3721943 is a prime.

3721945 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721943) 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, 372190 + ... + 372199.

It is an arithmetic number, because the mean of its divisors is an integer number (1116585).

Almost surely, 2^3721945 is an apocalyptic number.

It is an amenable number.

3721945 is a deficient number, since it is larger than the sum of its proper divisors (744395).

3721945 is an equidigital number, since it uses as much as digits as its factorization.

3721945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744394.

The product of its digits is 7560, while the sum is 31.

The square root of 3721945 is about 1929.2343040699. The cubic root of 3721945 is about 154.9732177104.

The spelling of 3721945 in words is "three million, seven hundred twenty-one thousand, nine hundred forty-five".