20825557499 has 8 divisors (see below), whose sum is σ = 20937682800. Its totient is φ = 20713476096.

The previous prime is 20825557469. The next prime is 20825557531. The reversal of 20825557499 is 99475552802.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20825557499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20825557439) 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, 1469204 + ... + 1483310.

It is an arithmetic number, because the mean of its divisors is an integer number (2617210350).

Almost surely, 2^20825557499 is an apocalyptic number.

20825557499 is a deficient number, since it is larger than the sum of its proper divisors (112125301).

20825557499 is a wasteful number, since it uses less digits than its factorization.

20825557499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21949.

The product of its (nonzero) digits is 9072000, while the sum is 56.

The spelling of 20825557499 in words is "twenty billion, eight hundred twenty-five million, five hundred fifty-seven thousand, four hundred ninety-nine".