97569781 has 2 divisors, whose sum is σ = 97569782. Its totient is φ = 97569780.

The previous prime is 97569757. The next prime is 97569809. The reversal of 97569781 is 18796579.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97416900 + 152881 = 9870^2 + 391^2 .

It is an emirp because it is prime and its reverse (18796579) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97569781 - 2⁷ = 97569653 is a prime.

It is a super-2 number, since 2×97569781² = 19039724328775922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97569281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48784890 + 48784891.

It is an arithmetic number, because the mean of its divisors is an integer number (48784891).

Almost surely, 2^97569781 is an apocalyptic number.

It is an amenable number.

97569781 is a deficient number, since it is larger than the sum of its proper divisors (1).

97569781 is an equidigital number, since it uses as much as digits as its factorization.

97569781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 952560, while the sum is 52.

The square root of 97569781 is about 9877.7416953472. The cubic root of 97569781 is about 460.3679805998.

It can be divided in two parts, 975 and 69781, that added together give a square (70756 = 266²).

The spelling of 97569781 in words is "ninety-seven million, five hundred sixty-nine thousand, seven hundred eighty-one".