1321531420 has 24 divisors (see below), whose sum is σ = 3027508848. Its totient is φ = 480556800.

The previous prime is 1321531411. The next prime is 1321531429. The reversal of 1321531420 is 241351231.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1321531411) and next prime (1321531429).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 1321531391 and 1321531400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321531429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3003261 + ... + 3003700.

It is an arithmetic number, because the mean of its divisors is an integer number (126146202).

Almost surely, 2^1321531420 is an apocalyptic number.

1321531420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321531420 is an abundant number, since it is smaller than the sum of its proper divisors (1705977428).

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

1321531420 is a wasteful number, since it uses less digits than its factorization.

1321531420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6006981 (or 6006979 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 1321531420 is about 36352.8736140625. The cubic root of 1321531420 is about 1097.3853658528.

Adding to 1321531420 its reverse (241351231), we get a palindrome (1562882651).

The spelling of 1321531420 in words is "one billion, three hundred twenty-one million, five hundred thirty-one thousand, four hundred twenty".