73521544021 has 4 divisors (see below), whose sum is σ = 73581367500. Its totient is φ = 73461720544.

The previous prime is 73521544013. The next prime is 73521544039. The reversal of 73521544021 is 12044512537.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 71639199025 + 1882344996 = 267655^2 + 43386^2 .

It is a cyclic number.

It is not a de Polignac number, because 73521544021 - 2³ = 73521544013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73521544001) 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, 29909896 + ... + 29912353.

It is an arithmetic number, because the mean of its divisors is an integer number (18395341875).

Almost surely, 2^73521544021 is an apocalyptic number.

It is an amenable number.

73521544021 is a deficient number, since it is larger than the sum of its proper divisors (59823479).

73521544021 is a wasteful number, since it uses less digits than its factorization.

73521544021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59823478.

The product of its (nonzero) digits is 33600, while the sum is 34.

The spelling of 73521544021 in words is "seventy-three billion, five hundred twenty-one million, five hundred forty-four thousand, twenty-one".