31428690 has 64 divisors (see below), whose sum is σ = 77746176. Its totient is φ = 8128512.

The previous prime is 31428689. The next prime is 31428703. The reversal of 31428690 is 9682413.

It is a super-2 number, since 2×31428690² = 1975525110232200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 247407 + ... + 247533.

It is an arithmetic number, because the mean of its divisors is an integer number (1214784).

Almost surely, 2^31428690 is an apocalyptic number.

31428690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31428690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38873088).

31428690 is an abundant number, since it is smaller than the sum of its proper divisors (46317486).

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

31428690 is a wasteful number, since it uses less digits than its factorization.

31428690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 31428690 is about 5606.1296809831. The cubic root of 31428690 is about 315.5794825711.

The spelling of 31428690 in words is "thirty-one million, four hundred twenty-eight thousand, six hundred ninety".