99121786 has 4 divisors (see below), whose sum is σ = 148682682. Its totient is φ = 49560892.

The previous prime is 99121783. The next prime is 99121801. The reversal of 99121786 is 68712199.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68712199 = 73 ⋅941263.

It can be written as a sum of positive squares in only one way, i.e., 98624761 + 497025 = 9931^2 + 705^2 .

It is not an unprimeable number, because it can be changed into a prime (99121783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24780445 + ... + 24780448.

Almost surely, 2^99121786 is an apocalyptic number.

99121786 is a deficient number, since it is larger than the sum of its proper divisors (49560896).

99121786 is a wasteful number, since it uses less digits than its factorization.

99121786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49560895.

The product of its digits is 54432, while the sum is 43.

The square root of 99121786 is about 9955.9924668513. The cubic root of 99121786 is about 462.7961167737.

The spelling of 99121786 in words is "ninety-nine million, one hundred twenty-one thousand, seven hundred eighty-six".