31840428 has 48 divisors (see below), whose sum is σ = 78624000. Its totient is φ = 10001088.

The previous prime is 31840427. The next prime is 31840429. The reversal of 31840428 is 82404813.

It is an interprime number because it is at equal distance from previous prime (31840427) and next prime (31840429).

It is a junction number, because it is equal to n+sod(n) for n = 31840395 and 31840404.

It is not an unprimeable number, because it can be changed into a prime (31840421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81658 + ... + 82046.

It is an arithmetic number, because the mean of its divisors is an integer number (1638000).

Almost surely, 2^31840428 is an apocalyptic number.

31840428 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31840428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39312000).

31840428 is an abundant number, since it is smaller than the sum of its proper divisors (46783572).

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

31840428 is a wasteful number, since it uses less digits than its factorization.

31840428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774 (or 772 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 31840428 is about 5642.7323168834. The cubic root of 31840428 is about 316.9516125264.

The spelling of 31840428 in words is "thirty-one million, eight hundred forty thousand, four hundred twenty-eight".