21727542 has 8 divisors (see below), whose sum is σ = 43455096. Its totient is φ = 7242512.

The previous prime is 21727493. The next prime is 21727543. The reversal of 21727542 is 24572712.

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

21727542 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21727543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1810623 + ... + 1810634.

It is an arithmetic number, because the mean of its divisors is an integer number (5431887).

Almost surely, 2^21727542 is an apocalyptic number.

21727542 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21727542 is a wasteful number, since it uses less digits than its factorization.

21727542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3621262.

The product of its digits is 7840, while the sum is 30.

The square root of 21727542 is about 4661.2811543609. The cubic root of 21727542 is about 279.0424005137.

The spelling of 21727542 in words is "twenty-one million, seven hundred twenty-seven thousand, five hundred forty-two".