2021011857 has 16 divisors (see below), whose sum is σ = 2994794880. Its totient is φ = 1347024816.

The previous prime is 2021011823. The next prime is 2021011873. The reversal of 2021011857 is 7581101202.

It is not a de Polignac number, because 2021011857 - 2⁶ = 2021011793 is a prime.

It is a super-2 number, since 2×2021011857² = 8168977852269176898, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 2021011857.

It is not an unprimeable number, because it can be changed into a prime (2021011897) 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, 190228 + ... + 200570.

It is an arithmetic number, because the mean of its divisors is an integer number (187174680).

Almost surely, 2^2021011857 is an apocalyptic number.

2021011857 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

2021011857 is a deficient number, since it is larger than the sum of its proper divisors (973783023).

2021011857 is a wasteful number, since it uses less digits than its factorization.

2021011857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17589 (or 17583 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 2021011857 is about 44955.6654605401. The cubic root of 2021011857 is about 1264.3179014746.

The spelling of 2021011857 in words is "two billion, twenty-one million, eleven thousand, eight hundred fifty-seven".