21000958540 has 24 divisors (see below), whose sum is σ = 44156426832. Its totient is φ = 8390018880.

The previous prime is 21000958513. The next prime is 21000958543. The reversal of 21000958540 is 4585900012.

It is a junction number, because it is equal to n+sod(n) for n = 21000958496 and 21000958505.

It is not an unprimeable number, because it can be changed into a prime (21000958543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 631159 + ... + 663598.

It is an arithmetic number, because the mean of its divisors is an integer number (1839851118).

Almost surely, 2^21000958540 is an apocalyptic number.

21000958540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000958540 is an abundant number, since it is smaller than the sum of its proper divisors (23155468292).

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

21000958540 is a wasteful number, since it uses less digits than its factorization.

21000958540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1295577 (or 1295575 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The spelling of 21000958540 in words is "twenty-one billion, nine hundred fifty-eight thousand, five hundred forty".