1221432525 has 72 divisors (see below), whose sum is σ = 2237249664. Its totient is φ = 636854400.

The previous prime is 1221432523. The next prime is 1221432631. The reversal of 1221432525 is 5252341221.

1221432525 is a `hidden beast` number, since 1 + 221 + 432 + 5 + 2 + 5 = 666.

It is not a de Polignac number, because 1221432525 - 2¹ = 1221432523 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221432523) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2507832 + ... + 2508318.

It is an arithmetic number, because the mean of its divisors is an integer number (31072912).

Almost surely, 2^1221432525 is an apocalyptic number.

1221432525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221432525 is a deficient number, since it is larger than the sum of its proper divisors (1015817139).

1221432525 is a wasteful number, since it uses less digits than its factorization.

1221432525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731 (or 723 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 1221432525 is about 34948.9989127013. The cubic root of 1221432525 is about 1068.9477893914.

Adding to 1221432525 its reverse (5252341221), we get a palindrome (6473773746).

The spelling of 1221432525 in words is "one billion, two hundred twenty-one million, four hundred thirty-two thousand, five hundred twenty-five".