21142857840 has 160 divisors (see below), whose sum is σ = 74736841536. Its totient is φ = 4898242560.

The previous prime is 21142857811. The next prime is 21142857851. The reversal of 21142857840 is 4875824112.

It is a junction number, because it is equal to n+sod(n) for n = 21142857792 and 21142857801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146271 + ... + 252350.

Almost surely, 2^21142857840 is an apocalyptic number.

21142857840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21142857840 is an abundant number, since it is smaller than the sum of its proper divisors (53593983696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21142857840 is a wasteful number, since it uses less digits than its factorization.

21142857840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398667 (or 398661 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 42.

The spelling of 21142857840 in words is "twenty-one billion, one hundred forty-two million, eight hundred fifty-seven thousand, eight hundred forty".