72861691 has 8 divisors (see below), whose sum is σ = 84443904. Its totient is φ = 61572840.

The previous prime is 72861673. The next prime is 72861707. The reversal of 72861691 is 19616827.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72861691 - 2¹¹ = 72859643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72861491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72805 + ... + 73798.

It is an arithmetic number, because the mean of its divisors is an integer number (10555488).

Almost surely, 2^72861691 is an apocalyptic number.

72861691 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

72861691 is a deficient number, since it is larger than the sum of its proper divisors (11582213).

72861691 is a wasteful number, since it uses less digits than its factorization.

72861691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146681.

The product of its digits is 36288, while the sum is 40.

The square root of 72861691 is about 8535.9059858928. The cubic root of 72861691 is about 417.6698074601.

The spelling of 72861691 in words is "seventy-two million, eight hundred sixty-one thousand, six hundred ninety-one".