21061339647 has 8 divisors (see below), whose sum is σ = 28082476800. Its totient is φ = 14040547800.

The previous prime is 21061339603. The next prime is 21061339657. The reversal of 21061339647 is 74693316012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21061339647 - 2¹⁴ = 21061323263 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21061339599 and 21061339608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061339657) 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, 143104 + ... + 250202.

It is an arithmetic number, because the mean of its divisors is an integer number (3510309600).

Almost surely, 2^21061339647 is an apocalyptic number.

21061339647 is a deficient number, since it is larger than the sum of its proper divisors (7021137153).

21061339647 is a wasteful number, since it uses less digits than its factorization.

21061339647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172653.

The product of its (nonzero) digits is 163296, while the sum is 42.

The spelling of 21061339647 in words is "twenty-one billion, sixty-one million, three hundred thirty-nine thousand, six hundred forty-seven".