31550420 has 48 divisors (see below), whose sum is σ = 73495296. Its totient is φ = 11280000.

The previous prime is 31550401. The next prime is 31550437. The reversal of 31550420 is 2405513.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31550392 and 31550401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12245 + ... + 14595.

It is an arithmetic number, because the mean of its divisors is an integer number (1531152).

Almost surely, 2^31550420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31550420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36747648).

31550420 is an abundant number, since it is smaller than the sum of its proper divisors (41944876).

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

31550420 is a wasteful number, since it uses less digits than its factorization.

31550420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2432 (or 2430 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 31550420 is about 5616.9760547825. The cubic root of 31550420 is about 315.9863931544.

Adding to 31550420 its reverse (2405513), we get a palindrome (33955933).

The spelling of 31550420 in words is "thirty-one million, five hundred fifty thousand, four hundred twenty".