97187721 has 16 divisors (see below), whose sum is σ = 132557568. Its totient is φ = 63320400.

The previous prime is 97187689. The next prime is 97187723. The reversal of 97187721 is 12778179.

It is not a de Polignac number, because 97187721 - 2⁵ = 97187689 is a prime.

It is a super-2 number, since 2×97187721² = 18890906226347682, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (97187723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24486 + ... + 28176.

It is an arithmetic number, because the mean of its divisors is an integer number (8284848).

Almost surely, 2^97187721 is an apocalyptic number.

It is an amenable number.

97187721 is a deficient number, since it is larger than the sum of its proper divisors (35369847).

97187721 is a wasteful number, since it uses less digits than its factorization.

97187721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3892.

The product of its digits is 49392, while the sum is 42.

The square root of 97187721 is about 9858.3832853060. The cubic root of 97187721 is about 459.7662974819.

The spelling of 97187721 in words is "ninety-seven million, one hundred eighty-seven thousand, seven hundred twenty-one".