21542755 has 16 divisors (see below), whose sum is σ = 28030464. Its totient is φ = 15799680.

The previous prime is 21542687. The next prime is 21542761. The reversal of 21542755 is 55724512.

It is not a de Polignac number, because 21542755 - 2¹⁹ = 21018467 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9150 + ... + 11260.

It is an arithmetic number, because the mean of its divisors is an integer number (1751904).

Almost surely, 2^21542755 is an apocalyptic number.

21542755 is a deficient number, since it is larger than the sum of its proper divisors (6487709).

21542755 is a wasteful number, since it uses less digits than its factorization.

21542755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2286.

The product of its digits is 14000, while the sum is 31.

The square root of 21542755 is about 4641.4173481815. The cubic root of 21542755 is about 278.2490866575.

The spelling of 21542755 in words is "twenty-one million, five hundred forty-two thousand, seven hundred fifty-five".