21200440534 has 64 divisors (see below), whose sum is σ = 40044533760. Its totient is φ = 8195120640.

The previous prime is 21200440507. The next prime is 21200440579. The reversal of 21200440534 is 43504400212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21200440499 and 21200440508.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1452927 + ... + 1467445.

It is an arithmetic number, because the mean of its divisors is an integer number (625695840).

Almost surely, 2^21200440534 is an apocalyptic number.

21200440534 is a deficient number, since it is larger than the sum of its proper divisors (18844093226).

21200440534 is a wasteful number, since it uses less digits than its factorization.

21200440534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14725.

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21200440534 its reverse (43504400212), we get a palindrome (64704840746).

The spelling of 21200440534 in words is "twenty-one billion, two hundred million, four hundred forty thousand, five hundred thirty-four".