21759477906 has 16 divisors (see below), whose sum is σ = 43525748448. Its totient is φ = 7252027200.

The previous prime is 21759477877. The next prime is 21759477907. The reversal of 21759477906 is 60977495712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21759477907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240900 + ... + 318671.

It is an arithmetic number, because the mean of its divisors is an integer number (2720359278).

Almost surely, 2^21759477906 is an apocalyptic number.

21759477906 is an abundant number, since it is smaller than the sum of its proper divisors (21766270542).

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

21759477906 is a wasteful number, since it uses less digits than its factorization.

21759477906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566057.

The product of its (nonzero) digits is 6667920, while the sum is 57.

The spelling of 21759477906 in words is "twenty-one billion, seven hundred fifty-nine million, four hundred seventy-seven thousand, nine hundred six".