3749821 has 4 divisors (see below), whose sum is σ = 3947200. Its totient is φ = 3552444.

The previous prime is 3749807. The next prime is 3749833. The reversal of 3749821 is 1289473.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1289473 = 19 ⋅67867.

It is a cyclic number.

It is not a de Polignac number, because 3749821 - 2⁹ = 3749309 is a prime.

It is a super-2 number, since 2×3749821² = 28122315064082, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3749861) 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, 98661 + ... + 98698.

It is an arithmetic number, because the mean of its divisors is an integer number (986800).

Almost surely, 2^3749821 is an apocalyptic number.

It is an amenable number.

3749821 is a deficient number, since it is larger than the sum of its proper divisors (197379).

3749821 is a wasteful number, since it uses less digits than its factorization.

3749821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197378.

The product of its digits is 12096, while the sum is 34.

The square root of 3749821 is about 1936.4454549509. The cubic root of 3749821 is about 155.3591532823.

The spelling of 3749821 in words is "three million, seven hundred forty-nine thousand, eight hundred twenty-one".