21059687061 has 24 divisors (see below), whose sum is σ = 34868393664. Its totient is φ = 11998385280.

The previous prime is 21059687021. The next prime is 21059687069. The reversal of 21059687061 is 16078695012.

It is not a de Polignac number, because 21059687061 - 2⁶ = 21059686997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21059686998 and 21059687016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21059687069) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 474735 + ... + 517196.

It is an arithmetic number, because the mean of its divisors is an integer number (1452849736).

Almost surely, 2^21059687061 is an apocalyptic number.

21059687061 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21059687061 is a deficient number, since it is larger than the sum of its proper divisors (13808706603).

21059687061 is a wasteful number, since it uses less digits than its factorization.

21059687061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992281 (or 992278 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 21059687061 in words is "twenty-one billion, fifty-nine million, six hundred eighty-seven thousand, sixty-one".