21077571 has 8 divisors (see below), whose sum is σ = 28272384. Its totient is φ = 13967240.

The previous prime is 21077561. The next prime is 21077599. The reversal of 21077571 is 17577012.

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 21077571 - 2¹⁰ = 21076547 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21077561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20535 + ... + 21536.

It is an arithmetic number, because the mean of its divisors is an integer number (3534048).

Almost surely, 2^21077571 is an apocalyptic number.

21077571 is a deficient number, since it is larger than the sum of its proper divisors (7194813).

21077571 is a wasteful number, since it uses less digits than its factorization.

21077571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42241.

The product of its (nonzero) digits is 3430, while the sum is 30.

The square root of 21077571 is about 4591.0315834244. The cubic root of 21077571 is about 276.2317026162.

The spelling of 21077571 in words is "twenty-one million, seventy-seven thousand, five hundred seventy-one".