20752421581 has 8 divisors (see below), whose sum is σ = 21107829600. Its totient is φ = 20397136080.

The previous prime is 20752421551. The next prime is 20752421593. The reversal of 20752421581 is 18512425702.

It is a happy number.

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 20752421581 - 2⁹ = 20752421069 is a prime.

It is a super-2 number, since 2×20752421581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20752421581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20752421551) 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, 351450 + ... + 406228.

It is an arithmetic number, because the mean of its divisors is an integer number (2638478700).

Almost surely, 2^20752421581 is an apocalyptic number.

It is an amenable number.

20752421581 is a deficient number, since it is larger than the sum of its proper divisors (355408019).

20752421581 is an equidigital number, since it uses as much as digits as its factorization.

20752421581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61259.

The product of its (nonzero) digits is 44800, while the sum is 37.

The spelling of 20752421581 in words is "twenty billion, seven hundred fifty-two million, four hundred twenty-one thousand, five hundred eighty-one".