21029470686 has 36 divisors (see below), whose sum is σ = 52077006072. Its totient is φ = 6007955112.

The previous prime is 21029470673. The next prime is 21029470691. The reversal of 21029470686 is 68607492012.

It is a happy number.

21029470686 is a `hidden beast` number, since 210 + 294 + 70 + 6 + 86 = 666.

It is a super-3 number, since 3×21029470686³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1621335 + ... + 1634253.

It is an arithmetic number, because the mean of its divisors is an integer number (1446583502).

Almost surely, 2^21029470686 is an apocalyptic number.

21029470686 is an abundant number, since it is smaller than the sum of its proper divisors (31047535386).

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

21029470686 is an frugal number, since it uses more digits than its factorization.

21029470686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25853 (or 12931 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21029470686 in words is "twenty-one billion, twenty-nine million, four hundred seventy thousand, six hundred eighty-six".