99427721 has 4 divisors (see below), whose sum is σ = 99481092. Its totient is φ = 99374352.

The previous prime is 99427709. The next prime is 99427723. The reversal of 99427721 is 12772499.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12772499 = 29 ⋅440431.

It can be written as a sum of positive squares in 2 ways, for example, as 85470025 + 13957696 = 9245^2 + 3736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99427721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99427723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23786 + ... + 27651.

It is an arithmetic number, because the mean of its divisors is an integer number (24870273).

Almost surely, 2^99427721 is an apocalyptic number.

It is an amenable number.

99427721 is a deficient number, since it is larger than the sum of its proper divisors (53371).

99427721 is a wasteful number, since it uses less digits than its factorization.

99427721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53370.

The product of its digits is 63504, while the sum is 41.

The square root of 99427721 is about 9971.3449945331. The cubic root of 99427721 is about 463.2717609926.

The spelling of 99427721 in words is "ninety-nine million, four hundred twenty-seven thousand, seven hundred twenty-one".