21237745043 has 4 divisors (see below), whose sum is σ = 21289671480. Its totient is φ = 21185818608.

The previous prime is 21237744967. The next prime is 21237745049. The reversal of 21237745043 is 34054773212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21237745043 - 2¹⁸ = 21237482899 is a prime.

It is a super-3 number, since 3×21237745043³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21237744988 and 21237745006.

It is not an unprimeable number, because it can be changed into a prime (21237745049) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 25962605 + ... + 25963422.

It is an arithmetic number, because the mean of its divisors is an integer number (5322417870).

Almost surely, 2^21237745043 is an apocalyptic number.

21237745043 is a deficient number, since it is larger than the sum of its proper divisors (51926437).

21237745043 is an equidigital number, since it uses as much as digits as its factorization.

21237745043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51926436.

The product of its (nonzero) digits is 141120, while the sum is 38.

The spelling of 21237745043 in words is "twenty-one billion, two hundred thirty-seven million, seven hundred forty-five thousand, forty-three".