21949790 has 8 divisors (see below), whose sum is σ = 39509640. Its totient is φ = 8779912.

The previous prime is 21949789. The next prime is 21949793. The reversal of 21949790 is 9794912.

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 not an unprimeable number, because it can be changed into a prime (21949793) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1097480 + ... + 1097499.

It is an arithmetic number, because the mean of its divisors is an integer number (4938705).

Almost surely, 2^21949790 is an apocalyptic number.

21949790 is a deficient number, since it is larger than the sum of its proper divisors (17559850).

21949790 is a wasteful number, since it uses less digits than its factorization.

21949790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2194986.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 21949790 is about 4685.0602984380. The cubic root of 21949790 is about 279.9906034262.

The spelling of 21949790 in words is "twenty-one million, nine hundred forty-nine thousand, seven hundred ninety".