21043503437 has 8 divisors (see below), whose sum is σ = 22960832160. Its totient is φ = 19126888560.

The previous prime is 21043503407. The next prime is 21043503491. The reversal of 21043503437 is 73430534012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21043503437 - 2⁶ = 21043503373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043503407) 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, 115862 + ... + 235607.

It is an arithmetic number, because the mean of its divisors is an integer number (2870104020).

Almost surely, 2^21043503437 is an apocalyptic number.

It is an amenable number.

21043503437 is a deficient number, since it is larger than the sum of its proper divisors (1917328723).

21043503437 is a wasteful number, since it uses less digits than its factorization.

21043503437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356923.

The product of its (nonzero) digits is 30240, while the sum is 32.

The spelling of 21043503437 in words is "twenty-one billion, forty-three million, five hundred three thousand, four hundred thirty-seven".