42512212781 has 4 divisors (see below), whose sum is σ = 43209134364. Its totient is φ = 41815291200.

The previous prime is 42512212753. The next prime is 42512212801. The reversal of 42512212781 is 18721221524.

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

It can be written as a sum of positive squares in 2 ways, for example, as 759829225 + 41752383556 = 27565^2 + 204334^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42512212781 is a prime.

It is a super-2 number, since 2×42512212781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42512212711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 348460700 + ... + 348460821.

It is an arithmetic number, because the mean of its divisors is an integer number (10802283591).

Almost surely, 2^42512212781 is an apocalyptic number.

It is an amenable number.

42512212781 is a deficient number, since it is larger than the sum of its proper divisors (696921583).

42512212781 is an equidigital number, since it uses as much as digits as its factorization.

42512212781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696921582.

The product of its digits is 17920, while the sum is 35.

The spelling of 42512212781 in words is "forty-two billion, five hundred twelve million, two hundred twelve thousand, seven hundred eighty-one".