21988879782 has 16 divisors (see below), whose sum is σ = 44913457152. Its totient is φ = 7173677000.

The previous prime is 21988879769. The next prime is 21988879799. The reversal of 21988879782 is 28797888912.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38987094 + ... + 38987657.

It is an arithmetic number, because the mean of its divisors is an integer number (2807091072).

Almost surely, 2^21988879782 is an apocalyptic number.

21988879782 is an abundant number, since it is smaller than the sum of its proper divisors (22924577370).

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

21988879782 is a wasteful number, since it uses less digits than its factorization.

21988879782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77974803.

The product of its digits is 65028096, while the sum is 69.

The spelling of 21988879782 in words is "twenty-one billion, nine hundred eighty-eight million, eight hundred seventy-nine thousand, seven hundred eighty-two".