21261416 has 32 divisors (see below), whose sum is σ = 43675200. Its totient is φ = 9623040.

The previous prime is 21261413. The next prime is 21261433. The reversal of 21261416 is 61416212.

It is a junction number, because it is equal to n+sod(n) for n = 21261391 and 21261400.

It is not an unprimeable number, because it can be changed into a prime (21261413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31256 + ... + 31928.

It is an arithmetic number, because the mean of its divisors is an integer number (1364850).

Almost surely, 2^21261416 is an apocalyptic number.

It is an amenable number.

21261416 is an abundant number, since it is smaller than the sum of its proper divisors (22413784).

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

21261416 is a wasteful number, since it uses less digits than its factorization.

21261416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1049 (or 1045 counting only the distinct ones).

The product of its digits is 576, while the sum is 23.

The square root of 21261416 is about 4611.0103014415. The cubic root of 21261416 is about 277.0325045375.

Adding to 21261416 its reverse (61416212), we get a palindrome (82677628).

The spelling of 21261416 in words is "twenty-one million, two hundred sixty-one thousand, four hundred sixteen".