21077655 has 16 divisors (see below), whose sum is σ = 34188000. Its totient is φ = 11086848.

The previous prime is 21077633. The next prime is 21077659. The reversal of 21077655 is 55677012.

It is not a de Polignac number, because 21077655 - 2⁷ = 21077527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21077659) by changing a digit.

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, 8530 + ... + 10719.

It is an arithmetic number, because the mean of its divisors is an integer number (2136750).

Almost surely, 2^21077655 is an apocalyptic number.

21077655 is a deficient number, since it is larger than the sum of its proper divisors (13110345).

21077655 is a wasteful number, since it uses less digits than its factorization.

21077655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19330.

The product of its (nonzero) digits is 14700, while the sum is 33.

The square root of 21077655 is about 4591.0407316860. The cubic root of 21077655 is about 276.2320695691.

The spelling of 21077655 in words is "twenty-one million, seventy-seven thousand, six hundred fifty-five".