72097961 has 4 divisors (see below), whose sum is σ = 77643972. Its totient is φ = 66551952.

The previous prime is 72097943. The next prime is 72098017. The reversal of 72097961 is 16979027.

It is a happy number.

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 41847961 + 30250000 = 6469^2 + 5500^2 .

It is a cyclic number.

It is not a de Polignac number, because 72097961 - 2¹⁸ = 71835817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72097061) 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, 2772986 + ... + 2773011.

It is an arithmetic number, because the mean of its divisors is an integer number (19410993).

Almost surely, 2^72097961 is an apocalyptic number.

It is an amenable number.

72097961 is a deficient number, since it is larger than the sum of its proper divisors (5546011).

72097961 is a wasteful number, since it uses less digits than its factorization.

72097961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5546010.

The product of its (nonzero) digits is 47628, while the sum is 41.

The square root of 72097961 is about 8491.0518194155. The cubic root of 72097961 is about 416.2053523401.

The spelling of 72097961 in words is "seventy-two million, ninety-seven thousand, nine hundred sixty-one".