7491032721 has 12 divisors (see below), whose sum is σ = 10957348480. Its totient is φ = 4930805880.

The previous prime is 7491032693. The next prime is 7491032729. The reversal of 7491032721 is 1272301947.

It is not a de Polignac number, because 7491032721 - 2¹⁵ = 7490999953 is a prime.

It is a super-2 number, since 2×7491032721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7491032729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5267245 + ... + 5268666.

Almost surely, 2^7491032721 is an apocalyptic number.

It is an amenable number.

7491032721 is a deficient number, since it is larger than the sum of its proper divisors (3466315759).

7491032721 is a wasteful number, since it uses less digits than its factorization.

7491032721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10535996 (or 10535993 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 7491032721 is about 86550.7522844256. The cubic root of 7491032721 is about 1956.6533825640.

The spelling of 7491032721 in words is "seven billion, four hundred ninety-one million, thirty-two thousand, seven hundred twenty-one".