31400424 has 96 divisors (see below), whose sum is σ = 95135040. Its totient is φ = 9273600.

The previous prime is 31400401. The next prime is 31400429. The reversal of 31400424 is 42400413.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31400397 and 31400406.

It is not an unprimeable number, because it can be changed into a prime (31400429) 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, 31989 + ... + 32955.

It is an arithmetic number, because the mean of its divisors is an integer number (990990).

Almost surely, 2^31400424 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 31400424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47567520).

31400424 is an abundant number, since it is smaller than the sum of its proper divisors (63734616).

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

31400424 is a wasteful number, since it uses less digits than its factorization.

31400424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031 (or 1024 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 31400424 is about 5603.6081233434. The cubic root of 31400424 is about 315.4848466915.

Adding to 31400424 its reverse (42400413), we get a palindrome (73800837).

It can be divided in two parts, 314004 and 24, that added together give a triangular number (314028 = T₇₉₂).

The spelling of 31400424 in words is "thirty-one million, four hundred thousand, four hundred twenty-four".