97287721 has 8 divisors (see below), whose sum is σ = 100787400. Its totient is φ = 93909424.

The previous prime is 97287709. The next prime is 97287727. The reversal of 97287721 is 12778279.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 48400 + 97239321 = 220^2 + 9861^2 .

It is not a de Polignac number, because 97287721 - 2¹³ = 97279529 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97287727) 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, 22395 + ... + 26383.

It is an arithmetic number, because the mean of its divisors is an integer number (12598425).

Almost surely, 2^97287721 is an apocalyptic number.

It is an amenable number.

97287721 is a deficient number, since it is larger than the sum of its proper divisors (3499679).

97287721 is an frugal number, since it uses more digits than its factorization.

97287721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4076 (or 4018 counting only the distinct ones).

The product of its digits is 98784, while the sum is 43.

The square root of 97287721 is about 9863.4538068569. The cubic root of 97287721 is about 459.9239335470.

The spelling of 97287721 in words is "ninety-seven million, two hundred eighty-seven thousand, seven hundred twenty-one".