99781273 has 2 divisors, whose sum is σ = 99781274. Its totient is φ = 99781272.

The previous prime is 99781271. The next prime is 99781301. The reversal of 99781273 is 37218799.

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., 54582544 + 45198729 = 7388^2 + 6723^2 .

It is a cyclic number.

It is not a de Polignac number, because 99781273 - 2¹ = 99781271 is a prime.

Together with 99781271, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (99781271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49890636 + 49890637.

It is an arithmetic number, because the mean of its divisors is an integer number (49890637).

Almost surely, 2^99781273 is an apocalyptic number.

It is an amenable number.

99781273 is a deficient number, since it is larger than the sum of its proper divisors (1).

99781273 is an equidigital number, since it uses as much as digits as its factorization.

99781273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 46.

The square root of 99781273 is about 9989.0576632633. The cubic root of 99781273 is about 463.8202227268.

The spelling of 99781273 in words is "ninety-nine million, seven hundred eighty-one thousand, two hundred seventy-three".