31220010 has 48 divisors (see below), whose sum is σ = 82218240. Its totient is φ = 8218080.

The previous prime is 31220003. The next prime is 31220011. The reversal of 31220010 is 1002213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 31219974 and 31220001.

It is not an unprimeable number, because it can be changed into a prime (31220011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4915 + ... + 9305.

It is an arithmetic number, because the mean of its divisors is an integer number (1712880).

Almost surely, 2^31220010 is an apocalyptic number.

31220010 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 31220010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41109120).

31220010 is an abundant number, since it is smaller than the sum of its proper divisors (50998230).

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

31220010 is a wasteful number, since it uses less digits than its factorization.

31220010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4483 (or 4480 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 31220010 is about 5587.4869127364. The cubic root of 31220010 is about 314.8794701379.

Adding to 31220010 its reverse (1002213), we get a palindrome (32222223).

The spelling of 31220010 in words is "thirty-one million, two hundred twenty thousand, ten".