7216521445 has 16 divisors (see below), whose sum is σ = 9993035520. Its totient is φ = 4900425984.

The previous prime is 7216521421. The next prime is 7216521449. The reversal of 7216521445 is 5441256127.

It is a cyclic number.

It is not a de Polignac number, because 7216521445 - 2⁵ = 7216521413 is a prime.

It is a super-2 number, since 2×7216521445² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7216521449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 997300 + ... + 1004509.

It is an arithmetic number, because the mean of its divisors is an integer number (624564720).

Almost surely, 2^7216521445 is an apocalyptic number.

It is an amenable number.

7216521445 is a deficient number, since it is larger than the sum of its proper divisors (2776514075).

7216521445 is a wasteful number, since it uses less digits than its factorization.

7216521445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001924.

The product of its digits is 67200, while the sum is 37.

The square root of 7216521445 is about 84950.1115066955. Note that the first 3 decimals coincide. The cubic root of 7216521445 is about 1932.4546112903.

The spelling of 7216521445 in words is "seven billion, two hundred sixteen million, five hundred twenty-one thousand, four hundred forty-five".