1221425442 has 48 divisors (see below), whose sum is σ = 2786921280. Its totient is φ = 385852896.

The previous prime is 1221425423. The next prime is 1221425459. The reversal of 1221425442 is 2445241221.

It is a happy number.

1221425442 is a `hidden beast` number, since 1 + 2 + 214 + 2 + 5 + 442 = 666.

It is a super-2 number, since 2×1221425442² = 2983760220729790728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31593 + ... + 58659.

It is an arithmetic number, because the mean of its divisors is an integer number (58060860).

Almost surely, 2^1221425442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221425442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1393460640).

1221425442 is an abundant number, since it is smaller than the sum of its proper divisors (1565495838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221425442 is a wasteful number, since it uses less digits than its factorization.

1221425442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27207 (or 27204 counting only the distinct ones).

The product of its digits is 5120, while the sum is 27.

The square root of 1221425442 is about 34948.8975791798. The cubic root of 1221425442 is about 1068.9457231367.

Adding to 1221425442 its reverse (2445241221), we get a palindrome (3666666663).

The spelling of 1221425442 in words is "one billion, two hundred twenty-one million, four hundred twenty-five thousand, four hundred forty-two".