42591961 has 2 divisors, whose sum is σ = 42591962. Its totient is φ = 42591960.

The previous prime is 42591959. The next prime is 42591971. The reversal of 42591961 is 16919524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41679936 + 912025 = 6456^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 42591961 - 2¹ = 42591959 is a prime.

Together with 42591959, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 42591961.

It is not a weakly prime, because it can be changed into another prime (42591931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21295980 + 21295981.

It is an arithmetic number, because the mean of its divisors is an integer number (21295981).

Almost surely, 2^42591961 is an apocalyptic number.

It is an amenable number.

42591961 is a deficient number, since it is larger than the sum of its proper divisors (1).

42591961 is an equidigital number, since it uses as much as digits as its factorization.

42591961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 37.

The square root of 42591961 is about 6526.2516807123. The cubic root of 42591961 is about 349.2281248410.

The spelling of 42591961 in words is "forty-two million, five hundred ninety-one thousand, nine hundred sixty-one".