42990394 has 4 divisors (see below), whose sum is σ = 64485594. Its totient is φ = 21495196.

The previous prime is 42990391. The next prime is 42990413. The reversal of 42990394 is 49309924.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 38601369 + 4389025 = 6213^2 + 2095^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (42990391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10747597 + ... + 10747600.

Almost surely, 2^42990394 is an apocalyptic number.

42990394 is a deficient number, since it is larger than the sum of its proper divisors (21495200).

42990394 is a wasteful number, since it uses less digits than its factorization.

42990394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21495199.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 42990394 is about 6556.7060327576. The cubic root of 42990394 is about 350.3137160014.

The spelling of 42990394 in words is "forty-two million, nine hundred ninety thousand, three hundred ninety-four".