97722781 has 4 divisors (see below), whose sum is σ = 105239932. Its totient is φ = 90205632.

The previous prime is 97722733. The next prime is 97722787. The reversal of 97722781 is 18722779.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18722779 = 47 ⋅398357.

It can be written as a sum of positive squares in 2 ways, for example, as 58660281 + 39062500 = 7659^2 + 6250^2 .

It is a cyclic number.

It is not a de Polignac number, because 97722781 - 2²³ = 89334173 is a prime.

It is a super-2 number, since 2×97722781² = 19099483852747922, 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 (97722787) 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, 3758556 + ... + 3758581.

It is an arithmetic number, because the mean of its divisors is an integer number (26309983).

Almost surely, 2^97722781 is an apocalyptic number.

It is an amenable number.

97722781 is a deficient number, since it is larger than the sum of its proper divisors (7517151).

97722781 is a wasteful number, since it uses less digits than its factorization.

97722781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7517150.

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

The square root of 97722781 is about 9885.4833468071. The cubic root of 97722781 is about 460.6084905716.

The spelling of 97722781 in words is "ninety-seven million, seven hundred twenty-two thousand, seven hundred eighty-one".