72497561 has 4 divisors (see below), whose sum is σ = 74836224. Its totient is φ = 70158900.

The previous prime is 72497549. The next prime is 72497573. The reversal of 72497561 is 16579427.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (72497549) and next prime (72497573).

It is a cyclic number.

It is not a de Polignac number, because 72497561 - 2¹⁴ = 72481177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72497501) 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, 1169285 + ... + 1169346.

It is an arithmetic number, because the mean of its divisors is an integer number (18709056).

Almost surely, 2^72497561 is an apocalyptic number.

It is an amenable number.

72497561 is a deficient number, since it is larger than the sum of its proper divisors (2338663).

72497561 is a wasteful number, since it uses less digits than its factorization.

72497561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338662.

The product of its digits is 105840, while the sum is 41.

The square root of 72497561 is about 8514.5499587471. The cubic root of 72497561 is about 416.9728698178.

The spelling of 72497561 in words is "seventy-two million, four hundred ninety-seven thousand, five hundred sixty-one".