99987973 has 2 divisors, whose sum is σ = 99987974. Its totient is φ = 99987972.

The previous prime is 99987961. The next prime is 99987983. The reversal of 99987973 is 37978999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56520324 + 43467649 = 7518^2 + 6593^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99987973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99987983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49993986 + 49993987.

It is an arithmetic number, because the mean of its divisors is an integer number (49993987).

Almost surely, 2^99987973 is an apocalyptic number.

It is an amenable number.

99987973 is a deficient number, since it is larger than the sum of its proper divisors (1).

99987973 is an equidigital number, since it uses as much as digits as its factorization.

99987973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7715736, while the sum is 61.

The square root of 99987973 is about 9999.3986319178. The cubic root of 99987973 is about 464.1402744856.

It can be divided in two parts, 9998 and 7973, that added together give a palindrome (17971).

The spelling of 99987973 in words is "ninety-nine million, nine hundred eighty-seven thousand, nine hundred seventy-three".