20867221857 has 16 divisors (see below), whose sum is σ = 28117277568. Its totient is φ = 13764508800.

The previous prime is 20867221841. The next prime is 20867221867. The reversal of 20867221857 is 75812276802.

It is not a de Polignac number, because 20867221857 - 2⁴ = 20867221841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20867221807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 445213 + ... + 489845.

It is an arithmetic number, because the mean of its divisors is an integer number (1757329848).

Almost surely, 2^20867221857 is an apocalyptic number.

It is an amenable number.

20867221857 is a deficient number, since it is larger than the sum of its proper divisors (7250055711).

20867221857 is a wasteful number, since it uses less digits than its factorization.

20867221857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46280.

The product of its (nonzero) digits is 752640, while the sum is 48.

Subtracting 20867221857 from its reverse (75812276802), we obtain a palindrome (54945054945).

The spelling of 20867221857 in words is "twenty billion, eight hundred sixty-seven million, two hundred twenty-one thousand, eight hundred fifty-seven".