99981757 has 2 divisors, whose sum is σ = 99981758. Its totient is φ = 99981756.

The previous prime is 99981701. The next prime is 99981787. The reversal of 99981757 is 75718999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 98922916 + 1058841 = 9946^2 + 1029^2 .

It is a cyclic number.

It is not a de Polignac number, because 99981757 - 2²³ = 91593149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 99981698 and 99981707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99981787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49990878 + 49990879.

It is an arithmetic number, because the mean of its divisors is an integer number (49990879).

Almost surely, 2^99981757 is an apocalyptic number.

It is an amenable number.

99981757 is a deficient number, since it is larger than the sum of its proper divisors (1).

99981757 is an equidigital number, since it uses as much as digits as its factorization.

99981757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1428840, while the sum is 55.

The square root of 99981757 is about 9999.0878083953. The cubic root of 99981757 is about 464.1306561430.

The spelling of 99981757 in words is "ninety-nine million, nine hundred eighty-one thousand, seven hundred fifty-seven".