72370561 has 4 divisors (see below), whose sum is σ = 72745732. Its totient is φ = 71995392.

The previous prime is 72370559. The next prime is 72370567. The reversal of 72370561 is 16507327.

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 47059600 + 25310961 = 6860^2 + 5031^2 .

It is a cyclic number.

It is not a de Polignac number, because 72370561 - 2¹ = 72370559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72370567) 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, 187296 + ... + 187681.

It is an arithmetic number, because the mean of its divisors is an integer number (18186433).

Almost surely, 2^72370561 is an apocalyptic number.

It is an amenable number.

72370561 is a deficient number, since it is larger than the sum of its proper divisors (375171).

72370561 is a wasteful number, since it uses less digits than its factorization.

72370561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375170.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 72370561 is about 8507.0888675269. The cubic root of 72370561 is about 416.7292454986.

Adding to 72370561 its reverse (16507327), we get a palindrome (88877888).

The spelling of 72370561 in words is "seventy-two million, three hundred seventy thousand, five hundred sixty-one".