21440473642 has 64 divisors (see below), whose sum is σ = 38578913280. Its totient is φ = 8743492800.

The previous prime is 21440473631. The next prime is 21440473643. The reversal of 21440473642 is 24637404412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21440473643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15683643 + ... + 15685009.

It is an arithmetic number, because the mean of its divisors is an integer number (602795520).

Almost surely, 2^21440473642 is an apocalyptic number.

21440473642 is a deficient number, since it is larger than the sum of its proper divisors (17138439638).

21440473642 is a wasteful number, since it uses less digits than its factorization.

21440473642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1987.

The product of its (nonzero) digits is 129024, while the sum is 37.

The spelling of 21440473642 in words is "twenty-one billion, four hundred forty million, four hundred seventy-three thousand, six hundred forty-two".