1221515343 has 8 divisors (see below), whose sum is σ = 1809652400. Its totient is φ = 814343544.

The previous prime is 1221515341. The next prime is 1221515359. The reversal of 1221515343 is 3435151221.

1221515343 is a `hidden beast` number, since 122 + 1 + 5 + 1 + 534 + 3 = 666.

It is not a de Polignac number, because 1221515343 - 2¹ = 1221515341 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 45241309 = 1221515343 / (1 + 2 + 2 + 1 + 5 + 1 + 5 + 3 + 4 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221515341) 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, 22620628 + ... + 22620681.

It is an arithmetic number, because the mean of its divisors is an integer number (226206550).

Almost surely, 2^1221515343 is an apocalyptic number.

1221515343 is a deficient number, since it is larger than the sum of its proper divisors (588137057).

1221515343 is an equidigital number, since it uses as much as digits as its factorization.

1221515343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45241318 (or 45241312 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 1221515343 is about 34950.1837334226. The cubic root of 1221515343 is about 1068.9719484875.

Adding to 1221515343 its reverse (3435151221), we get a palindrome (4656666564).

The spelling of 1221515343 in words is "one billion, two hundred twenty-one million, five hundred fifteen thousand, three hundred forty-three".