21746427 has 8 divisors (see below), whose sum is σ = 29062464. Its totient is φ = 14464008.

The previous prime is 21746423. The next prime is 21746429. The reversal of 21746427 is 72464712.

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

It is not a de Polignac number, because 21746427 - 2² = 21746423 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21746423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6853 + ... + 9510.

It is an arithmetic number, because the mean of its divisors is an integer number (3632808).

Almost surely, 2^21746427 is an apocalyptic number.

21746427 is a deficient number, since it is larger than the sum of its proper divisors (7316037).

21746427 is a wasteful number, since it uses less digits than its factorization.

21746427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16809.

The product of its digits is 18816, while the sum is 33.

The square root of 21746427 is about 4663.3064450023. The cubic root of 21746427 is about 279.1232225061.

The spelling of 21746427 in words is "twenty-one million, seven hundred forty-six thousand, four hundred twenty-seven".