21918046 has 12 divisors (see below), whose sum is σ = 33665112. Its totient is φ = 10702356.

The previous prime is 21918037. The next prime is 21918053. The reversal of 21918046 is 64081912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21917999 and 21918017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 735 + ... + 6661.

It is an arithmetic number, because the mean of its divisors is an integer number (2805426).

Almost surely, 2^21918046 is an apocalyptic number.

21918046 is a deficient number, since it is larger than the sum of its proper divisors (11747066).

21918046 is an equidigital number, since it uses as much as digits as its factorization.

21918046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6015 (or 5972 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 21918046 is about 4681.6712827793. The cubic root of 21918046 is about 279.8555632609.

Adding to 21918046 its reverse (64081912), we get a palindrome (85999958).

The spelling of 21918046 in words is "twenty-one million, nine hundred eighteen thousand, forty-six".