31121430 has 64 divisors (see below), whose sum is σ = 79833600. Its totient is φ = 7741440.

The previous prime is 31121413. The next prime is 31121479. The reversal of 31121430 is 3412113.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40086 + ... + 40854.

It is an arithmetic number, because the mean of its divisors is an integer number (1247400).

Almost surely, 2^31121430 is an apocalyptic number.

31121430 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 31121430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39916800).

31121430 is an abundant number, since it is smaller than the sum of its proper divisors (48712170).

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

31121430 is a wasteful number, since it uses less digits than its factorization.

31121430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 31121430 is about 5578.6584408799. The cubic root of 31121430 is about 314.5477005774.

Adding to 31121430 its reverse (3412113), we get a palindrome (34533543).

The spelling of 31121430 in words is "thirty-one million, one hundred twenty-one thousand, four hundred thirty".