21891746 has 8 divisors (see below), whose sum is σ = 32859984. Its totient is φ = 10938420.

The previous prime is 21891719. The next prime is 21891757. The reversal of 21891746 is 64719812.

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

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, 1301 + ... + 6743.

It is an arithmetic number, because the mean of its divisors is an integer number (4107498).

Almost surely, 2^21891746 is an apocalyptic number.

21891746 is a deficient number, since it is larger than the sum of its proper divisors (10968238).

21891746 is a wasteful number, since it uses less digits than its factorization.

21891746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7456.

The product of its digits is 24192, while the sum is 38.

The square root of 21891746 is about 4678.8616136834. The cubic root of 21891746 is about 279.7435832791.

The spelling of 21891746 in words is "twenty-one million, eight hundred ninety-one thousand, seven hundred forty-six".