42187969 has 2 divisors, whose sum is σ = 42187970. Its totient is φ = 42187968.

The previous prime is 42187967. The next prime is 42187979. The reversal of 42187969 is 96978124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26884225 + 15303744 = 5185^2 + 3912^2 .

It is a cyclic number.

It is not a de Polignac number, because 42187969 - 2¹ = 42187967 is a prime.

It is a super-2 number, since 2×42187969² = 3559649456689922, which contains 22 as substring.

Together with 42187967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42187963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21093984 + 21093985.

It is an arithmetic number, because the mean of its divisors is an integer number (21093985).

Almost surely, 2^42187969 is an apocalyptic number.

It is an amenable number.

42187969 is a deficient number, since it is larger than the sum of its proper divisors (1).

42187969 is an equidigital number, since it uses as much as digits as its factorization.

42187969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 42187969 is about 6495.2266319198. The cubic root of 42187969 is about 348.1204525341.

The spelling of 42187969 in words is "forty-two million, one hundred eighty-seven thousand, nine hundred sixty-nine".