21763878 has 16 divisors (see below), whose sum is σ = 44178240. Its totient is φ = 7146216.

The previous prime is 21763871. The next prime is 21763883. The reversal of 21763878 is 87836712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21763871) 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, 26668 + ... + 27471.

It is an arithmetic number, because the mean of its divisors is an integer number (2761140).

Almost surely, 2^21763878 is an apocalyptic number.

21763878 is an abundant number, since it is smaller than the sum of its proper divisors (22414362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21763878 is a wasteful number, since it uses less digits than its factorization.

21763878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54211.

The product of its digits is 112896, while the sum is 42.

The square root of 21763878 is about 4665.1771670538. The cubic root of 21763878 is about 279.1978658332.

The spelling of 21763878 in words is "twenty-one million, seven hundred sixty-three thousand, eight hundred seventy-eight".