99039781 has 4 divisors (see below), whose sum is σ = 99185472. Its totient is φ = 98894092.

The previous prime is 99039779. The next prime is 99039791. The reversal of 99039781 is 18793099.

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.

It is a cyclic number.

It is not a de Polignac number, because 99039781 - 2¹ = 99039779 is a prime.

It is a super-2 number, since 2×99039781² = 19617756441055922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99039791) 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, 71821 + ... + 73186.

It is an arithmetic number, because the mean of its divisors is an integer number (24796368).

Almost surely, 2^99039781 is an apocalyptic number.

99039781 is the 5320-th centered heptagonal number.

It is an amenable number.

99039781 is a deficient number, since it is larger than the sum of its proper divisors (145691).

99039781 is a wasteful number, since it uses less digits than its factorization.

99039781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145690.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 99039781 is about 9951.8732407522. The cubic root of 99039781 is about 462.6684554126.

The spelling of 99039781 in words is "ninety-nine million, thirty-nine thousand, seven hundred eighty-one".