30811872 has 96 divisors (see below), whose sum is σ = 99574272. Its totient is φ = 8123904.

The previous prime is 30811867. The next prime is 30811873. The reversal of 30811872 is 27811803.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×30811872² = 1898742912288768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30811873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6973 + ... + 10499.

It is an arithmetic number, because the mean of its divisors is an integer number (1037232).

Almost surely, 2^30811872 is an apocalyptic number.

30811872 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30811872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49787136).

30811872 is an abundant number, since it is smaller than the sum of its proper divisors (68762400).

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

30811872 is a wasteful number, since it uses less digits than its factorization.

30811872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3560 (or 3552 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 30811872 is about 5550.8442601103. The cubic root of 30811872 is about 313.5013112689.

The spelling of 30811872 in words is "thirty million, eight hundred eleven thousand, eight hundred seventy-two".