42139973 has 2 divisors, whose sum is σ = 42139974. Its totient is φ = 42139972.

The previous prime is 42139939. The next prime is 42140017. The reversal of 42139973 is 37993124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35259844 + 6880129 = 5938^2 + 2623^2 .

It is a cyclic number.

It is not a de Polignac number, because 42139973 - 2¹⁶ = 42074437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42139913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21069986 + 21069987.

It is an arithmetic number, because the mean of its divisors is an integer number (21069987).

Almost surely, 2^42139973 is an apocalyptic number.

It is an amenable number.

42139973 is a deficient number, since it is larger than the sum of its proper divisors (1).

42139973 is an equidigital number, since it uses as much as digits as its factorization.

42139973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 42139973 is about 6491.5308672146. The cubic root of 42139973 is about 347.9883870040.

The spelling of 42139973 in words is "forty-two million, one hundred thirty-nine thousand, nine hundred seventy-three".