99921973 has 2 divisors, whose sum is σ = 99921974. Its totient is φ = 99921972.

The previous prime is 99921947. The next prime is 99922001. The reversal of 99921973 is 37912999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71267364 + 28654609 = 8442^2 + 5353^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99921973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99921373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49960986 + 49960987.

It is an arithmetic number, because the mean of its divisors is an integer number (49960987).

Almost surely, 2^99921973 is an apocalyptic number.

It is an amenable number.

99921973 is a deficient number, since it is larger than the sum of its proper divisors (1).

99921973 is an equidigital number, since it uses as much as digits as its factorization.

99921973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 275562, while the sum is 49.

The square root of 99921973 is about 9996.0978886764. The cubic root of 99921973 is about 464.0381288648.

The spelling of 99921973 in words is "ninety-nine million, nine hundred twenty-one thousand, nine hundred seventy-three".