21546791 has 8 divisors (see below), whose sum is σ = 25695744. Its totient is φ = 17665560.

The previous prime is 21546787. The next prime is 21546823. The reversal of 21546791 is 19764512.

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

It is a cyclic number.

It is not a de Polignac number, because 21546791 - 2² = 21546787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21546751) 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, 66755 + ... + 67076.

It is an arithmetic number, because the mean of its divisors is an integer number (3211968).

Almost surely, 2^21546791 is an apocalyptic number.

21546791 is a deficient number, since it is larger than the sum of its proper divisors (4148953).

21546791 is a wasteful number, since it uses less digits than its factorization.

21546791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133861.

The product of its digits is 15120, while the sum is 35.

The square root of 21546791 is about 4641.8521088031. The cubic root of 21546791 is about 278.2664620766.

The spelling of 21546791 in words is "twenty-one million, five hundred forty-six thousand, seven hundred ninety-one".