72891645 has 64 divisors (see below), whose sum is σ = 127491840. Its totient is φ = 35481600.

The previous prime is 72891629. The next prime is 72891673. The reversal of 72891645 is 54619827.

It is not a de Polignac number, because 72891645 - 2⁴ = 72891629 is a prime.

It is a super-3 number, since 3×72891645³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 72891597 and 72891606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1087902 + ... + 1087968.

It is an arithmetic number, because the mean of its divisors is an integer number (1992060).

Almost surely, 2^72891645 is an apocalyptic number.

It is an amenable number.

72891645 is a deficient number, since it is larger than the sum of its proper divisors (54600195).

72891645 is a wasteful number, since it uses less digits than its factorization.

72891645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206.

The product of its digits is 120960, while the sum is 42.

The square root of 72891645 is about 8537.6603938081. The cubic root of 72891645 is about 417.7270353723.

It can be divided in two parts, 72891 and 645, that added together give a triangular number (73536 = T₃₈₃).

The spelling of 72891645 in words is "seventy-two million, eight hundred ninety-one thousand, six hundred forty-five".