1221013425 has 24 divisors (see below), whose sum is σ = 2026629216. Its totient is φ = 648663040.

The previous prime is 1221013421. The next prime is 1221013439. The reversal of 1221013425 is 5243101221.

It is not a de Polignac number, because 1221013425 - 2² = 1221013421 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221013421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12399 + ... + 50948.

It is an arithmetic number, because the mean of its divisors is an integer number (84442884).

Almost surely, 2^1221013425 is an apocalyptic number.

1221013425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221013425 is a deficient number, since it is larger than the sum of its proper divisors (805615791).

1221013425 is a wasteful number, since it uses less digits than its factorization.

1221013425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63617 (or 63612 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1221013425 is about 34943.0025183870. The cubic root of 1221013425 is about 1068.8255156791.

Adding to 1221013425 its reverse (5243101221), we get a palindrome (6464114646).

The spelling of 1221013425 in words is "one billion, two hundred twenty-one million, thirteen thousand, four hundred twenty-five".