1221624545 has 16 divisors (see below), whose sum is σ = 1475496000. Its totient is φ = 970955328.

The previous prime is 1221624497. The next prime is 1221624587. The reversal of 1221624545 is 5454261221.

It is a cyclic number.

It is not a de Polignac number, because 1221624545 - 2²² = 1217430241 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 753746 + ... + 755364.

It is an arithmetic number, because the mean of its divisors is an integer number (92218500).

Almost surely, 2^1221624545 is an apocalyptic number.

It is an amenable number.

1221624545 is a deficient number, since it is larger than the sum of its proper divisors (253871455).

1221624545 is a wasteful number, since it uses less digits than its factorization.

1221624545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2512.

The product of its digits is 19200, while the sum is 32.

The square root of 1221624545 is about 34951.7459506675. The cubic root of 1221624545 is about 1069.0038024730.

Adding to 1221624545 its reverse (5454261221), we get a palindrome (6675885766).

The spelling of 1221624545 in words is "one billion, two hundred twenty-one million, six hundred twenty-four thousand, five hundred forty-five".