20689851247 has 8 divisors (see below), whose sum is σ = 22755450816. Its totient is φ = 18691976352.

The previous prime is 20689851209. The next prime is 20689851251. The reversal of 20689851247 is 74215898602.

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

It is a cyclic number.

It is not a de Polignac number, because 20689851247 - 2²⁷ = 20555633519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20689851194 and 20689851203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689851257) 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, 16930528 + ... + 16931749.

It is an arithmetic number, because the mean of its divisors is an integer number (2844431352).

Almost surely, 2^20689851247 is an apocalyptic number.

20689851247 is a deficient number, since it is larger than the sum of its proper divisors (2065599569).

20689851247 is a wasteful number, since it uses less digits than its factorization.

20689851247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33862337.

The product of its (nonzero) digits is 1935360, while the sum is 52.

The spelling of 20689851247 in words is "twenty billion, six hundred eighty-nine million, eight hundred fifty-one thousand, two hundred forty-seven".