31998742 has 4 divisors (see below), whose sum is σ = 47998116. Its totient is φ = 15999370.

The previous prime is 31998739. The next prime is 31998749. The reversal of 31998742 is 24789913.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24789913 = 313 ⋅79201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31998749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7999684 + ... + 7999687.

It is an arithmetic number, because the mean of its divisors is an integer number (11999529).

Almost surely, 2^31998742 is an apocalyptic number.

31998742 is a deficient number, since it is larger than the sum of its proper divisors (15999374).

31998742 is a wasteful number, since it uses less digits than its factorization.

31998742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15999373.

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

The square root of 31998742 is about 5656.7430558582. The cubic root of 31998742 is about 317.4760500255.

The spelling of 31998742 in words is "thirty-one million, nine hundred ninety-eight thousand, seven hundred forty-two".