7407721 has 4 divisors (see below), whose sum is σ = 7518352. Its totient is φ = 7297092.

The previous prime is 7407713. The next prime is 7407761. The reversal of 7407721 is 1277047.

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: 1277047 = 19 ⋅67213.

It is a cyclic number.

It is not a de Polignac number, because 7407721 - 2³ = 7407713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7407721.

It is not an unprimeable number, because it can be changed into a prime (7407761) 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, 55215 + ... + 55348.

It is an arithmetic number, because the mean of its divisors is an integer number (1879588).

Almost surely, 2^7407721 is an apocalyptic number.

It is an amenable number.

7407721 is a deficient number, since it is larger than the sum of its proper divisors (110631).

7407721 is a wasteful number, since it uses less digits than its factorization.

7407721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110630.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 7407721 is about 2721.7128797873. The cubic root of 7407721 is about 194.9372666929.

It can be divided in two parts, 7407 and 721, that added together give a triangular number (8128 = T₁₂₇).

The spelling of 7407721 in words is "seven million, four hundred seven thousand, seven hundred twenty-one".