20015774857 has 16 divisors (see below), whose sum is σ = 23610439440. Its totient is φ = 16789635072.

The previous prime is 20015774843. The next prime is 20015774887. The reversal of 20015774857 is 75847751002.

It can be written as a sum of positive squares in 8 ways, for example, as 2244485376 + 17771289481 = 47376^2 + 133309^2 .

It is a cyclic number.

It is not a de Polignac number, because 20015774857 - 2⁷ = 20015774729 is a prime.

It is a super-2 number, since 2×20015774857² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20015774887) 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, 1555128 + ... + 1567945.

It is an arithmetic number, because the mean of its divisors is an integer number (1475652465).

Almost surely, 2^20015774857 is an apocalyptic number.

It is an amenable number.

20015774857 is a deficient number, since it is larger than the sum of its proper divisors (3594664583).

20015774857 is a wasteful number, since it uses less digits than its factorization.

20015774857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3123132.

The product of its (nonzero) digits is 548800, while the sum is 46.

The spelling of 20015774857 in words is "twenty billion, fifteen million, seven hundred seventy-four thousand, eight hundred fifty-seven".