72073997 has 4 divisors (see below), whose sum is σ = 72140796. Its totient is φ = 72007200.

The previous prime is 72073993. The next prime is 72074003. The reversal of 72073997 is 79937027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79937027 = 5297 ⋅15091.

It can be written as a sum of positive squares in 2 ways, for example, as 48706441 + 23367556 = 6979^2 + 4834^2 .

It is a cyclic number.

It is not a de Polignac number, because 72073997 - 2² = 72073993 is a prime.

It is a super-2 number, since 2×72073997² = 10389322087112018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72073993) 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, 31754 + ... + 33947.

It is an arithmetic number, because the mean of its divisors is an integer number (18035199).

Almost surely, 2^72073997 is an apocalyptic number.

It is an amenable number.

72073997 is a deficient number, since it is larger than the sum of its proper divisors (66799).

72073997 is a wasteful number, since it uses less digits than its factorization.

72073997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66798.

The product of its (nonzero) digits is 166698, while the sum is 44.

The square root of 72073997 is about 8489.6405695412. The cubic root of 72073997 is about 416.1592342984.

The spelling of 72073997 in words is "seventy-two million, seventy-three thousand, nine hundred ninety-seven".