72171601 has 4 divisors (see below), whose sum is σ = 73354804. Its totient is φ = 70988400.

The previous prime is 72171563. The next prime is 72171611. The reversal of 72171601 is 10617127.

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 29986576 + 42185025 = 5476^2 + 6495^2 .

It is a cyclic number.

It is not a de Polignac number, because 72171601 - 2⁹ = 72171089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72171611) 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, 591510 + ... + 591631.

It is an arithmetic number, because the mean of its divisors is an integer number (18338701).

Almost surely, 2^72171601 is an apocalyptic number.

It is an amenable number.

72171601 is a deficient number, since it is larger than the sum of its proper divisors (1183203).

72171601 is a wasteful number, since it uses less digits than its factorization.

72171601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1183202.

The product of its (nonzero) digits is 588, while the sum is 25.

The square root of 72171601 is about 8495.3870423895. The cubic root of 72171601 is about 416.3470065222.

Adding to 72171601 its reverse (10617127), we get a palindrome (82788728).

The spelling of 72171601 in words is "seventy-two million, one hundred seventy-one thousand, six hundred one".