21003843240 has 128 divisors (see below), whose sum is σ = 70972156800. Its totient is φ = 5524277760.

The previous prime is 21003843233. The next prime is 21003843319. The reversal of 21003843240 is 4234830012.

21003843240 is a `hidden beast` number, since 210 + 0 + 384 + 32 + 40 = 666.

It is a super-2 number, since 2×21003843240² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54366 + ... + 212045.

It is an arithmetic number, because the mean of its divisors is an integer number (554469975).

Almost surely, 2^21003843240 is an apocalyptic number.

21003843240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21003843240 is an abundant number, since it is smaller than the sum of its proper divisors (49968313560).

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

21003843240 is a wasteful number, since it uses less digits than its factorization.

21003843240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266504 (or 266494 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The spelling of 21003843240 in words is "twenty-one billion, three million, eight hundred forty-three thousand, two hundred forty".