21161934 has 48 divisors (see below), whose sum is σ = 49420800. Its totient is φ = 6522768.

The previous prime is 21161927. The next prime is 21161939. The reversal of 21161934 is 43916112.

21161934 is a `hidden beast` number, since 2 + 11 + 619 + 34 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21161898 and 21161907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13987 + ... + 15425.

It is an arithmetic number, because the mean of its divisors is an integer number (1029600).

Almost surely, 2^21161934 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21161934, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24710400).

21161934 is an abundant number, since it is smaller than the sum of its proper divisors (28258866).

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

21161934 is a wasteful number, since it uses less digits than its factorization.

21161934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1509 (or 1506 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 21161934 is about 4600.2102125881. The cubic root of 21161934 is about 276.5997512400.

The spelling of 21161934 in words is "twenty-one million, one hundred sixty-one thousand, nine hundred thirty-four".