21769755 has 16 divisors (see below), whose sum is σ = 39807744. Its totient is φ = 9951840.

The previous prime is 21769751. The next prime is 21769757. The reversal of 21769755 is 55796712.

It is not a de Polignac number, because 21769755 - 2² = 21769751 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21769751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103561 + ... + 103770.

It is an arithmetic number, because the mean of its divisors is an integer number (2487984).

Almost surely, 2^21769755 is an apocalyptic number.

21769755 is a deficient number, since it is larger than the sum of its proper divisors (18037989).

21769755 is a wasteful number, since it uses less digits than its factorization.

21769755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207346.

The product of its digits is 132300, while the sum is 42.

The square root of 21769755 is about 4665.8070041527. The cubic root of 21769755 is about 279.2229945991. Note that the first 3 decimals are identical.

The spelling of 21769755 in words is "twenty-one million, seven hundred sixty-nine thousand, seven hundred fifty-five".