42013991 has 2 divisors, whose sum is σ = 42013992. Its totient is φ = 42013990.

The previous prime is 42013969. The next prime is 42013999. The reversal of 42013991 is 19931024.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42013991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42013999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21006995 + 21006996.

It is an arithmetic number, because the mean of its divisors is an integer number (21006996).

Almost surely, 2^42013991 is an apocalyptic number.

42013991 is a deficient number, since it is larger than the sum of its proper divisors (1).

42013991 is an equidigital number, since it uses as much as digits as its factorization.

42013991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 42013991 is about 6481.8200376129. The cubic root of 42013991 is about 347.6412578931.

It can be divided in two parts, 4201 and 3991, that added together give a 13-th power (8192 = 2¹³).

The spelling of 42013991 in words is "forty-two million, thirteen thousand, nine hundred ninety-one".