42090177781 has 4 divisors (see below), whose sum is σ = 42136380864. Its totient is φ = 42043974700.

The previous prime is 42090177761. The next prime is 42090177791. The reversal of 42090177781 is 18777109024.

42090177781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42090177781 is a prime.

It is a super-2 number, since 2×42090177781² (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 (42090177761) 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, 23100175 + ... + 23101996.

It is an arithmetic number, because the mean of its divisors is an integer number (10534095216).

Almost surely, 2^42090177781 is an apocalyptic number.

It is an amenable number.

42090177781 is a deficient number, since it is larger than the sum of its proper divisors (46203083).

42090177781 is an equidigital number, since it uses as much as digits as its factorization.

42090177781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46203082.

The product of its (nonzero) digits is 197568, while the sum is 46.

The spelling of 42090177781 in words is "forty-two billion, ninety million, one hundred seventy-seven thousand, seven hundred eighty-one".