21653510642 has 16 divisors (see below), whose sum is σ = 32970293952. Its totient is φ = 10663464240.

The previous prime is 21653510617. The next prime is 21653510653. The reversal of 21653510642 is 24601535612.

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 in 7 ways as a sum of consecutive naturals, for example, 1453592 + ... + 1468412.

It is an arithmetic number, because the mean of its divisors is an integer number (2060643372).

Almost surely, 2^21653510642 is an apocalyptic number.

21653510642 is a deficient number, since it is larger than the sum of its proper divisors (11316783310).

21653510642 is a wasteful number, since it uses less digits than its factorization.

21653510642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25793.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 21653510642 in words is "twenty-one billion, six hundred fifty-three million, five hundred ten thousand, six hundred forty-two".