21226015766 has 16 divisors (see below), whose sum is σ = 32870197248. Its totient is φ = 10269369000.

The previous prime is 21226015763. The next prime is 21226015847. The reversal of 21226015766 is 66751062212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226015763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 644291 + ... + 676433.

It is an arithmetic number, because the mean of its divisors is an integer number (2054387328).

Almost surely, 2^21226015766 is an apocalyptic number.

21226015766 is a deficient number, since it is larger than the sum of its proper divisors (11644181482).

21226015766 is a wasteful number, since it uses less digits than its factorization.

21226015766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42827.

The product of its (nonzero) digits is 60480, while the sum is 38.

Adding to 21226015766 its reverse (66751062212), we get a palindrome (87977077978).

The spelling of 21226015766 in words is "twenty-one billion, two hundred twenty-six million, fifteen thousand, seven hundred sixty-six".