7091235721 has 4 divisors (see below), whose sum is σ = 7508367252. Its totient is φ = 6674104192.

The previous prime is 7091235637. The next prime is 7091235757. The reversal of 7091235721 is 1275321907.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1275321907 = 43 ⋅29658649.

It can be written as a sum of positive squares in 2 ways, for example, as 4088195721 + 3003040000 = 63939^2 + 54800^2 .

It is a cyclic number.

It is not a de Polignac number, because 7091235721 - 2¹⁵ = 7091202953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7091235761) 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, 208565740 + ... + 208565773.

It is an arithmetic number, because the mean of its divisors is an integer number (1877091813).

Almost surely, 2^7091235721 is an apocalyptic number.

It is an amenable number.

7091235721 is a deficient number, since it is larger than the sum of its proper divisors (417131531).

7091235721 is a wasteful number, since it uses less digits than its factorization.

7091235721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417131530.

The product of its (nonzero) digits is 26460, while the sum is 37.

The square root of 7091235721 is about 84209.4752447728. The cubic root of 7091235721 is about 1921.2061757859.

The spelling of 7091235721 in words is "seven billion, ninety-one million, two hundred thirty-five thousand, seven hundred twenty-one".