31143390 has 32 divisors (see below), whose sum is σ = 77323680. Its totient is φ = 8018304.

The previous prime is 31143379. The next prime is 31143391. The reversal of 31143390 is 9334113.

Added to its reverse (9334113) it gives a triangular number (40477503 = T₈₉₉₇).

It is a self number, because there is not a number n which added to its sum of digits gives 31143390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31143391) 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 in 15 ways as a sum of consecutive naturals, for example, 17029 + ... + 18768.

It is an arithmetic number, because the mean of its divisors is an integer number (2416365).

Almost surely, 2^31143390 is an apocalyptic number.

31143390 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

31143390 is an abundant number, since it is smaller than the sum of its proper divisors (46180290).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31143390 is a wasteful number, since it uses less digits than its factorization.

31143390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35836.

The product of its (nonzero) digits is 972, while the sum is 24.

The square root of 31143390 is about 5580.6263089370. The cubic root of 31143390 is about 314.6216672241.

Adding to 31143390 its reverse (9334113), we get a triangular number (40477503 = T₈₉₉₇).

The spelling of 31143390 in words is "thirty-one million, one hundred forty-three thousand, three hundred ninety".