21661146 has 24 divisors (see below), whose sum is σ = 50543220. Its totient is φ = 6664896.

The previous prime is 21661141. The next prime is 21661151. The reversal of 21661146 is 64116612.

21661146 is a `hidden beast` number, since 2 + 1 + 6 + 611 + 46 = 666.

It is an interprime number because it is at equal distance from previous prime (21661141) and next prime (21661151).

It can be written as a sum of positive squares in 2 ways, for example, as 17313921 + 4347225 = 4161^2 + 2085^2 .

It is not an unprimeable number, because it can be changed into a prime (21661141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46051 + ... + 46518.

Almost surely, 2^21661146 is an apocalyptic number.

21661146 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21661146 is an abundant number, since it is smaller than the sum of its proper divisors (28882074).

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

21661146 is a wasteful number, since it uses less digits than its factorization.

21661146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92590 (or 92587 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 21661146 is about 4654.1536287493. The cubic root of 21661146 is about 278.7578737210.

Adding to 21661146 its reverse (64116612), we get a palindrome (85777758).

The spelling of 21661146 in words is "twenty-one million, six hundred sixty-one thousand, one hundred forty-six".