21229790 has 8 divisors (see below), whose sum is σ = 38213640. Its totient is φ = 8491912.

The previous prime is 21229777. The next prime is 21229829. The reversal of 21229790 is 9792212.

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

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, 1061480 + ... + 1061499.

It is an arithmetic number, because the mean of its divisors is an integer number (4776705).

Almost surely, 2^21229790 is an apocalyptic number.

21229790 is a deficient number, since it is larger than the sum of its proper divisors (16983850).

21229790 is a wasteful number, since it uses less digits than its factorization.

21229790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122986.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 21229790 is about 4607.5796249224. The cubic root of 21229790 is about 276.8950759714.

The spelling of 21229790 in words is "twenty-one million, two hundred twenty-nine thousand, seven hundred ninety".