21746947 has 8 divisors (see below), whose sum is σ = 22291776. Its totient is φ = 21205632.

The previous prime is 21746941. The next prime is 21746957. The reversal of 21746947 is 74964712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21746947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21746941) 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, 15153 + ... + 16525.

It is an arithmetic number, because the mean of its divisors is an integer number (2786472).

Almost surely, 2^21746947 is an apocalyptic number.

21746947 is a deficient number, since it is larger than the sum of its proper divisors (544829).

21746947 is a wasteful number, since it uses less digits than its factorization.

21746947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757.

The product of its digits is 84672, while the sum is 40.

The square root of 21746947 is about 4663.3621991006. The cubic root of 21746947 is about 279.1254472842.

The spelling of 21746947 in words is "twenty-one million, seven hundred forty-six thousand, nine hundred forty-seven".