72821721025 has 27 divisors (see below), whose sum is σ = 93359390409. Its totient is φ = 56345724000.

The previous prime is 72821721001. The next prime is 72821721047. The reversal of 72821721025 is 52012712827.

The square root of 72821721025 is 269855.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 44214734529 + 28606986496 = 210273^2 + 169136^2 .

It is not a de Polignac number, because 72821721025 - 2¹³ = 72821712833 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 41826655 + ... + 41828395.

Almost surely, 2^72821721025 is an apocalyptic number.

72821721025 is the 269855-th square number.

72821721025 is the 134928-th centered octagonal number.

It is an amenable number.

72821721025 is a deficient number, since it is larger than the sum of its proper divisors (20537669384).

72821721025 is an frugal number, since it uses more digits than its factorization.

72821721025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3554 (or 1777 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 37.

The spelling of 72821721025 in words is "seventy-two billion, eight hundred twenty-one million, seven hundred twenty-one thousand, twenty-five".