1221440542525 has 12 divisors (see below), whose sum is σ = 1730955740512. Its totient is φ = 837559229040.

The previous prime is 1221440542493. The next prime is 1221440542537. The reversal of 1221440542525 is 5252450441221.

It is not a de Polignac number, because 1221440542525 - 2⁵ = 1221440542493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3489829947 + ... + 3489830296.

Almost surely, 2^{1221440542525} is an apocalyptic number.

It is an amenable number.

1221440542525 is a deficient number, since it is larger than the sum of its proper divisors (509515197987).

1221440542525 is an equidigital number, since it uses as much as digits as its factorization.

1221440542525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6979660260 (or 6979660255 counting only the distinct ones).

The product of its (nonzero) digits is 128000, while the sum is 37.

Adding to 1221440542525 its reverse (5252450441221), we get a palindrome (6473890983746).

The spelling of 1221440542525 in words is "one trillion, two hundred twenty-one billion, four hundred forty million, five hundred forty-two thousand, five hundred twenty-five".