21377755 has 64 divisors (see below), whose sum is σ = 34283520. Its totient is φ = 12441600.

The previous prime is 21377731. The next prime is 21377767. The reversal of 21377755 is 55777312.

It is not a de Polignac number, because 21377755 - 2⁵ = 21377723 is a prime.

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 63 ways as a sum of consecutive naturals, for example, 350425 + ... + 350485.

It is an arithmetic number, because the mean of its divisors is an integer number (535680).

Almost surely, 2^21377755 is an apocalyptic number.

21377755 is a deficient number, since it is larger than the sum of its proper divisors (12905765).

21377755 is a wasteful number, since it uses less digits than its factorization.

21377755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140.

The product of its digits is 51450, while the sum is 37.

The square root of 21377755 is about 4623.6084393037. The cubic root of 21377755 is about 277.5368779277.

The spelling of 21377755 in words is "twenty-one million, three hundred seventy-seven thousand, seven hundred fifty-five".