21025543740 has 48 divisors (see below), whose sum is σ = 60307420320. Its totient is φ = 5470059520.

The previous prime is 21025543733. The next prime is 21025543787. The reversal of 21025543740 is 4734552012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4271025 + ... + 4275944.

It is an arithmetic number, because the mean of its divisors is an integer number (1256404590).

Almost surely, 2^21025543740 is an apocalyptic number.

21025543740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21025543740 is an abundant number, since it is smaller than the sum of its proper divisors (39281876580).

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

21025543740 is a wasteful number, since it uses less digits than its factorization.

21025543740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8547022 (or 8547020 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 33.

The spelling of 21025543740 in words is "twenty-one billion, twenty-five million, five hundred forty-three thousand, seven hundred forty".