42121969 has 2 divisors, whose sum is σ = 42121970. Its totient is φ = 42121968.

The previous prime is 42121951. The next prime is 42121979. The reversal of 42121969 is 96912124.

42121969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39187600 + 2934369 = 6260^2 + 1713^2 .

It is a cyclic number.

It is not a de Polignac number, because 42121969 - 2¹⁹ = 41597681 is a prime.

It is a super-2 number, since 2×42121969² = 3548520544873922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (42121939) 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, 21060984 + 21060985.

It is an arithmetic number, because the mean of its divisors is an integer number (21060985).

Almost surely, 2^42121969 is an apocalyptic number.

It is an amenable number.

42121969 is a deficient number, since it is larger than the sum of its proper divisors (1).

42121969 is an equidigital number, since it uses as much as digits as its factorization.

42121969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 42121969 is about 6490.1439891577. The cubic root of 42121969 is about 347.9388214337.

The spelling of 42121969 in words is "forty-two million, one hundred twenty-one thousand, nine hundred sixty-nine".