72561553 has 2 divisors, whose sum is σ = 72561554. Its totient is φ = 72561552.

The previous prime is 72561547. The next prime is 72561557. The reversal of 72561553 is 35516527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71774784 + 786769 = 8472^2 + 887^2 .

It is a cyclic number.

It is not a de Polignac number, because 72561553 - 2⁵ = 72561521 is a prime.

It is not a weakly prime, because it can be changed into another prime (72561557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36280776 + 36280777.

It is an arithmetic number, because the mean of its divisors is an integer number (36280777).

Almost surely, 2^72561553 is an apocalyptic number.

It is an amenable number.

72561553 is a deficient number, since it is larger than the sum of its proper divisors (1).

72561553 is an equidigital number, since it uses as much as digits as its factorization.

72561553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31500, while the sum is 34.

The square root of 72561553 is about 8518.3069327185. The cubic root of 72561553 is about 417.0955179940.

The spelling of 72561553 in words is "seventy-two million, five hundred sixty-one thousand, five hundred fifty-three".