21661046 has 8 divisors (see below), whose sum is σ = 35445384. Its totient is φ = 9845920.

The previous prime is 21661037. The next prime is 21661051. The reversal of 21661046 is 64016612.

It is a happy number.

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

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, 492275 + ... + 492318.

It is an arithmetic number, because the mean of its divisors is an integer number (4430673).

Almost surely, 2^21661046 is an apocalyptic number.

21661046 is a deficient number, since it is larger than the sum of its proper divisors (13784338).

21661046 is a wasteful number, since it uses less digits than its factorization.

21661046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984606.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21661046 is about 4654.1428856450. The cubic root of 21661046 is about 278.7574447528.

Adding to 21661046 its reverse (64016612), we get a palindrome (85677658).

The spelling of 21661046 in words is "twenty-one million, six hundred sixty-one thousand, forty-six".