21712394 has 8 divisors (see below), whose sum is σ = 35529408. Its totient is φ = 9869260.

The previous prime is 21712393. The next prime is 21712423. The reversal of 21712394 is 49321712.

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

It is a super-2 number, since 2×21712394² = 942856106422472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21712393) 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 3 ways as a sum of consecutive naturals, for example, 493442 + ... + 493485.

It is an arithmetic number, because the mean of its divisors is an integer number (4441176).

Almost surely, 2^21712394 is an apocalyptic number.

21712394 is a deficient number, since it is larger than the sum of its proper divisors (13817014).

21712394 is a wasteful number, since it uses less digits than its factorization.

21712394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986940.

The product of its digits is 3024, while the sum is 29.

The square root of 21712394 is about 4659.6559958864. The cubic root of 21712394 is about 278.9775378772.

The spelling of 21712394 in words is "twenty-one million, seven hundred twelve thousand, three hundred ninety-four".