20657210249 has 4 divisors (see below), whose sum is σ = 22246226436. Its totient is φ = 19068194064.

The previous prime is 20657210243. The next prime is 20657210269. The reversal of 20657210249 is 94201275602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9107839225 + 11549371024 = 95435^2 + 107468^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20657210249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20657210243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 794508074 + ... + 794508099.

It is an arithmetic number, because the mean of its divisors is an integer number (5561556609).

Almost surely, 2^20657210249 is an apocalyptic number.

It is an amenable number.

20657210249 is a deficient number, since it is larger than the sum of its proper divisors (1589016187).

20657210249 is a wasteful number, since it uses less digits than its factorization.

20657210249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589016186.

The product of its (nonzero) digits is 60480, while the sum is 38.

The spelling of 20657210249 in words is "twenty billion, six hundred fifty-seven million, two hundred ten thousand, two hundred forty-nine".