97821287 has 4 divisors (see below), whose sum is σ = 98718840. Its totient is φ = 96923736.

The previous prime is 97821221. The next prime is 97821313. The reversal of 97821287 is 78212879.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78212879 = 5167 ⋅15137.

It is a cyclic number.

It is not a de Polignac number, because 97821287 - 2¹² = 97817191 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 (97821487) 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, 448613 + ... + 448830.

It is an arithmetic number, because the mean of its divisors is an integer number (24679710).

Almost surely, 2^97821287 is an apocalyptic number.

97821287 is a deficient number, since it is larger than the sum of its proper divisors (897553).

97821287 is a wasteful number, since it uses less digits than its factorization.

97821287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897552.

The product of its digits is 112896, while the sum is 44.

The square root of 97821287 is about 9890.4644481440. The cubic root of 97821287 is about 460.7632053085.

The spelling of 97821287 in words is "ninety-seven million, eight hundred twenty-one thousand, two hundred eighty-seven".