97390781 has 2 divisors, whose sum is σ = 97390782. Its totient is φ = 97390780.

The previous prime is 97390757. The next prime is 97390801. The reversal of 97390781 is 18709379.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92256025 + 5134756 = 9605^2 + 2266^2 .

It is a cyclic number.

It is not a de Polignac number, because 97390781 - 2¹⁴ = 97374397 is a prime.

It is a super-2 number, since 2×97390781² = 18969928447579922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97390681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48695390 + 48695391.

It is an arithmetic number, because the mean of its divisors is an integer number (48695391).

Almost surely, 2^97390781 is an apocalyptic number.

It is an amenable number.

97390781 is a deficient number, since it is larger than the sum of its proper divisors (1).

97390781 is an equidigital number, since it uses as much as digits as its factorization.

97390781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 97390781 is about 9868.6767603362. The cubic root of 97390781 is about 460.0862802871.

The spelling of 97390781 in words is "ninety-seven million, three hundred ninety thousand, seven hundred eighty-one".