21630778534 has 16 divisors (see below), whose sum is σ = 32588430336. Its totient is φ = 10768048200.

The previous prime is 21630778531. The next prime is 21630778579. The reversal of 21630778534 is 43587703612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21630778531) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 540019 + ... + 578689.

It is an arithmetic number, because the mean of its divisors is an integer number (2036776896).

Almost surely, 2^21630778534 is an apocalyptic number.

21630778534 is a deficient number, since it is larger than the sum of its proper divisors (10957651802).

21630778534 is a wasteful number, since it uses less digits than its factorization.

21630778534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39891.

The product of its (nonzero) digits is 846720, while the sum is 46.

The spelling of 21630778534 in words is "twenty-one billion, six hundred thirty million, seven hundred seventy-eight thousand, five hundred thirty-four".