1356221538 has 48 divisors (see below), whose sum is σ = 3360741696. Its totient is φ = 387205920.

The previous prime is 1356221467. The next prime is 1356221549. The reversal of 1356221538 is 8351226531.

1356221538 is a `hidden beast` number, since 13 + 5 + 622 + 15 + 3 + 8 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 215253 + ... + 221463.

It is an arithmetic number, because the mean of its divisors is an integer number (70015452).

Almost surely, 2^1356221538 is an apocalyptic number.

1356221538 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1356221538 is an abundant number, since it is smaller than the sum of its proper divisors (2004520158).

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

1356221538 is a wasteful number, since it uses less digits than its factorization.

1356221538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7959 (or 7956 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 1356221538 is about 36826.9132293218. The cubic root of 1356221538 is about 1106.9046512226.

The spelling of 1356221538 in words is "one billion, three hundred fifty-six million, two hundred twenty-one thousand, five hundred thirty-eight".