42581619991 has 2 divisors, whose sum is σ = 42581619992. Its totient is φ = 42581619990.

The previous prime is 42581619961. The next prime is 42581620001. The reversal of 42581619991 is 19991618524.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42581619991 - 2⁵ = 42581619959 is a prime.

It is a super-2 number, since 2×42581619991² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42581619931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21290809995 + 21290809996.

It is an arithmetic number, because the mean of its divisors is an integer number (21290809996).

Almost surely, 2^42581619991 is an apocalyptic number.

42581619991 is a deficient number, since it is larger than the sum of its proper divisors (1).

42581619991 is an equidigital number, since it uses as much as digits as its factorization.

42581619991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 55.

The spelling of 42581619991 in words is "forty-two billion, five hundred eighty-one million, six hundred nineteen thousand, nine hundred ninety-one".