99858721 has 4 divisors (see below), whose sum is σ = 99936432. Its totient is φ = 99781012.

The previous prime is 99858701. The next prime is 99858727. The reversal of 99858721 is 12785899.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12785899 = 7 ⋅1826557.

It is a cyclic number.

It is not a de Polignac number, because 99858721 - 2¹⁵ = 99825953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99858727) 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, 36895 + ... + 39508.

It is an arithmetic number, because the mean of its divisors is an integer number (24984108).

Almost surely, 2^99858721 is an apocalyptic number.

It is an amenable number.

99858721 is a deficient number, since it is larger than the sum of its proper divisors (77711).

99858721 is a wasteful number, since it uses less digits than its factorization.

99858721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77710.

The product of its digits is 362880, while the sum is 49.

The square root of 99858721 is about 9992.9335532665. The cubic root of 99858721 is about 463.9401939986.

The spelling of 99858721 in words is "ninety-nine million, eight hundred fifty-eight thousand, seven hundred twenty-one".