1221288523 has 16 divisors (see below), whose sum is σ = 1568480256. Its totient is φ = 924279840.

The previous prime is 1221288473. The next prime is 1221288533. The reversal of 1221288523 is 3258821221.

It is not a de Polignac number, because 1221288523 - 2⁹ = 1221288011 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221288533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289663 + ... + 293848.

It is an arithmetic number, because the mean of its divisors is an integer number (98030016).

Almost surely, 2^1221288523 is an apocalyptic number.

1221288523 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1221288523 is a deficient number, since it is larger than the sum of its proper divisors (347191733).

1221288523 is a wasteful number, since it uses less digits than its factorization.

1221288523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583554.

The product of its digits is 15360, while the sum is 34.

The square root of 1221288523 is about 34946.9386785166. The cubic root of 1221288523 is about 1068.9057795202.

The spelling of 1221288523 in words is "one billion, two hundred twenty-one million, two hundred eighty-eight thousand, five hundred twenty-three".