21694650 has 48 divisors (see below), whose sum is σ = 54707808. Its totient is φ = 5688000.

The previous prime is 21694633. The next prime is 21694657. The reversal of 21694650 is 5649612.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21694657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7965 + ... + 10335.

It is an arithmetic number, because the mean of its divisors is an integer number (1139746).

Almost surely, 2^21694650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21694650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27353904).

21694650 is an abundant number, since it is smaller than the sum of its proper divisors (33013158).

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

21694650 is a wasteful number, since it uses less digits than its factorization.

21694650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2447 (or 2442 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 21694650 is about 4657.7516035100. The cubic root of 21694650 is about 278.9015209792.

The spelling of 21694650 in words is "twenty-one million, six hundred ninety-four thousand, six hundred fifty".