21759477894 has 96 divisors (see below), whose sum is σ = 58817041920. Its totient is φ = 5648140800.

The previous prime is 21759477877. The next prime is 21759477907. The reversal of 21759477894 is 49877495712.

21759477894 is a `hidden beast` number, since 2 + 1 + 75 + 9 + 477 + 8 + 94 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2613999 + ... + 2622309.

It is an arithmetic number, because the mean of its divisors is an integer number (612677520).

Almost surely, 2^21759477894 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21759477894, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29408520960).

21759477894 is an abundant number, since it is smaller than the sum of its proper divisors (37057564026).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21759477894 is a wasteful number, since it uses less digits than its factorization.

21759477894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10226 (or 10223 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 21759477894 in words is "twenty-one billion, seven hundred fifty-nine million, four hundred seventy-seven thousand, eight hundred ninety-four".