72643601 has 4 divisors (see below), whose sum is σ = 76916772. Its totient is φ = 68370432.

The previous prime is 72643559. The next prime is 72643607. The reversal of 72643601 is 10634627.

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 62410000 + 10233601 = 7900^2 + 3199^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72643601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72643607) 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, 2136560 + ... + 2136593.

It is an arithmetic number, because the mean of its divisors is an integer number (19229193).

Almost surely, 2^72643601 is an apocalyptic number.

It is an amenable number.

72643601 is a deficient number, since it is larger than the sum of its proper divisors (4273171).

72643601 is a wasteful number, since it uses less digits than its factorization.

72643601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4273170.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 72643601 is about 8523.1215525768. The cubic root of 72643601 is about 417.2526671596.

The spelling of 72643601 in words is "seventy-two million, six hundred forty-three thousand, six hundred one".