21091046 has 8 divisors (see below), whose sum is σ = 33012144. Its totient is φ = 10087000.

The previous prime is 21091009. The next prime is 21091051. The reversal of 21091046 is 64019012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 229205 + ... + 229296.

It is an arithmetic number, because the mean of its divisors is an integer number (4126518).

Almost surely, 2^21091046 is an apocalyptic number.

21091046 is a deficient number, since it is larger than the sum of its proper divisors (11921098).

21091046 is a wasteful number, since it uses less digits than its factorization.

21091046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458526.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21091046 is about 4592.4988840499. The cubic root of 21091046 is about 276.2905555277.

The spelling of 21091046 in words is "twenty-one million, ninety-one thousand, forty-six".