21757754 has 4 divisors (see below), whose sum is σ = 32636634. Its totient is φ = 10878876.

The previous prime is 21757733. The next prime is 21757783. The reversal of 21757754 is 45775712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15642025 + 6115729 = 3955^2 + 2473^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5439437 + ... + 5439440.

Almost surely, 2^21757754 is an apocalyptic number.

21757754 is a deficient number, since it is larger than the sum of its proper divisors (10878880).

21757754 is a wasteful number, since it uses less digits than its factorization.

21757754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10878879.

The product of its digits is 68600, while the sum is 38.

The square root of 21757754 is about 4664.5207685249. The cubic root of 21757754 is about 279.1716761359.

The spelling of 21757754 in words is "twenty-one million, seven hundred fifty-seven thousand, seven hundred fifty-four".