684129942 has 64 divisors (see below), whose sum is σ = 1545734400. Its totient is φ = 224259840.

The previous prime is 684129937. The next prime is 684129947. The reversal of 684129942 is 249921486.

It is an interprime number because it is at equal distance from previous prime (684129937) and next prime (684129947).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684129947) 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 31 ways as a sum of consecutive naturals, for example, 1104909 + ... + 1105527.

It is an arithmetic number, because the mean of its divisors is an integer number (24152100).

Almost surely, 2^684129942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684129942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (772867200).

684129942 is an abundant number, since it is smaller than the sum of its proper divisors (861604458).

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

684129942 is a wasteful number, since it uses less digits than its factorization.

684129942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938 (or 932 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 684129942 is about 26155.8777715450. The cubic root of 684129942 is about 881.1426023941.

The spelling of 684129942 in words is "six hundred eighty-four million, one hundred twenty-nine thousand, nine hundred forty-two".