21055205734 has 8 divisors (see below), whose sum is σ = 32054194008. Its totient is φ = 10370474400.

The previous prime is 21055205729. The next prime is 21055205741. The reversal of 21055205734 is 43750255012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21055205734.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78564067 + ... + 78564334.

It is an arithmetic number, because the mean of its divisors is an integer number (4006774251).

Almost surely, 2^21055205734 is an apocalyptic number.

21055205734 is a deficient number, since it is larger than the sum of its proper divisors (10998988274).

21055205734 is a wasteful number, since it uses less digits than its factorization.

21055205734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157128470.

The product of its (nonzero) digits is 42000, while the sum is 34.

The spelling of 21055205734 in words is "twenty-one billion, fifty-five million, two hundred five thousand, seven hundred thirty-four".