21858729786 has 24 divisors (see below), whose sum is σ = 47372217984. Its totient is φ = 7284453000.

The previous prime is 21858729757. The next prime is 21858729793. The reversal of 21858729786 is 68792785812.

21858729786 is a `hidden beast` number, since 21 + 8 + 587 + 29 + 7 + 8 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72840 + ... + 221411.

It is an arithmetic number, because the mean of its divisors is an integer number (1973842416).

Almost surely, 2^21858729786 is an apocalyptic number.

21858729786 is an abundant number, since it is smaller than the sum of its proper divisors (25513488198).

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

21858729786 is a wasteful number, since it uses less digits than its factorization.

21858729786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298386 (or 298383 counting only the distinct ones).

The product of its digits is 27095040, while the sum is 63.

The spelling of 21858729786 in words is "twenty-one billion, eight hundred fifty-eight million, seven hundred twenty-nine thousand, seven hundred eighty-six".