9991893402 has 128 divisors (see below), whose sum is σ = 23659806720. Its totient is φ = 3120586560.

The previous prime is 9991893347. The next prime is 9991893407. The reversal of 9991893402 is 2043981999.

It is a super-2 number, since 2×9991893402² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (9991893407) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9141168 + ... + 9142260.

It is an arithmetic number, because the mean of its divisors is an integer number (184842240).

Almost surely, 2^9991893402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9991893402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11829903360).

9991893402 is an abundant number, since it is smaller than the sum of its proper divisors (13667913318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9991893402 is a wasteful number, since it uses less digits than its factorization.

9991893402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305 (or 1299 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The square root of 9991893402 is about 99959.4587920523. The cubic root of 9991893402 is about 2153.8523614484.

The spelling of 9991893402 in words is "nine billion, nine hundred ninety-one million, eight hundred ninety-three thousand, four hundred two".