99921947 has 2 divisors, whose sum is σ = 99921948.
Its totient is φ = 99921946.
The previous prime is 99921929. The next prime is 99921973. The reversal of 99921947 is 74912999.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 99921947 - 26 = 99921883 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 99921895 and 99921904.
It is not a weakly prime, because it can be changed into another prime (99921047) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49960973 + 49960974.
It is an arithmetic number, because the mean of its divisors is an integer number (49960974).
Almost surely, 299921947 is an apocalyptic number.
99921947 is a deficient number, since it is larger than the sum of its proper divisors (1).
99921947 is an equidigital number, since it uses as much as digits as its factorization.
99921947 is an evil number, because the sum of its binary digits is even.
The product of its digits is 367416, while the sum is 50.
The square root of 99921947 is about 9996.0965881688.
The cubic root of 99921947 is about 464.0380886168.
The spelling of 99921947 in words is "ninety-nine million, nine hundred twenty-one thousand, nine hundred forty-seven".