97447781 has 2 divisors, whose sum is σ = 97447782. Its totient is φ = 97447780.

The previous prime is 97447771. The next prime is 97447783. The reversal of 97447781 is 18774479.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84015556 + 13432225 = 9166^2 + 3665^2 .

It is a cyclic number.

It is not a de Polignac number, because 97447781 - 2⁶ = 97447717 is a prime.

It is a super-2 number, since 2×97447781² = 18992140043647922, which contains 22 as substring.

Together with 97447783, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 97447781 parts by 13960 straight cuts.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97447783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48723890 + 48723891.

It is an arithmetic number, because the mean of its divisors is an integer number (48723891).

Almost surely, 2^97447781 is an apocalyptic number.

It is an amenable number.

97447781 is a deficient number, since it is larger than the sum of its proper divisors (1).

97447781 is an equidigital number, since it uses as much as digits as its factorization.

97447781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 47.

The square root of 97447781 is about 9871.5642630740. The cubic root of 97447781 is about 460.1760211679.

The spelling of 97447781 in words is "ninety-seven million, four hundred forty-seven thousand, seven hundred eighty-one".