7921749 has 24 divisors (see below), whose sum is σ = 11767840. Its totient is φ = 4736160.

The previous prime is 7921723. The next prime is 7921757. The reversal of 7921749 is 9471297.

It is not a de Polignac number, because 7921749 - 2⁷ = 7921621 is a prime.

It is a Duffinian number.

7921749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7921759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50379 + ... + 50535.

Almost surely, 2^7921749 is an apocalyptic number.

It is an amenable number.

7921749 is a deficient number, since it is larger than the sum of its proper divisors (3846091).

7921749 is a wasteful number, since it uses less digits than its factorization.

7921749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 310 counting only the distinct ones).

The product of its digits is 31752, while the sum is 39.

The square root of 7921749 is about 2814.5601787846. The cubic root of 7921749 is about 199.3457705862.

It can be divided in two parts, 79 and 21749, that multiplied together give a palindrome (1718171).

The spelling of 7921749 in words is "seven million, nine hundred twenty-one thousand, seven hundred forty-nine".