42979381 has 2 divisors, whose sum is σ = 42979382. Its totient is φ = 42979380.

The previous prime is 42979379. The next prime is 42979399. The reversal of 42979381 is 18397924.

42979381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42693156 + 286225 = 6534^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 42979381 - 2¹ = 42979379 is a prime.

It is a super-2 number, since 2×42979381² = 3694454382286322, which contains 22 as substring.

Together with 42979379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42979301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21489690 + 21489691.

It is an arithmetic number, because the mean of its divisors is an integer number (21489691).

Almost surely, 2^42979381 is an apocalyptic number.

It is an amenable number.

42979381 is a deficient number, since it is larger than the sum of its proper divisors (1).

42979381 is an equidigital number, since it uses as much as digits as its factorization.

42979381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 42979381 is about 6555.8661517758. The cubic root of 42979381 is about 350.2837997489.

The spelling of 42979381 in words is "forty-two million, nine hundred seventy-nine thousand, three hundred eighty-one".