1221634425 has 48 divisors (see below), whose sum is σ = 2279407680. Its totient is φ = 571872000.

The previous prime is 1221634423. The next prime is 1221634457. The reversal of 1221634425 is 5244361221.

It is not a de Polignac number, because 1221634425 - 2¹ = 1221634423 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221634392 and 1221634401.

It is not an unprimeable number, because it can be changed into a prime (1221634423) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1606 + ... + 49455.

It is an arithmetic number, because the mean of its divisors is an integer number (47487660).

Almost surely, 2^1221634425 is an apocalyptic number.

1221634425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221634425 is a deficient number, since it is larger than the sum of its proper divisors (1057773255).

1221634425 is a wasteful number, since it uses less digits than its factorization.

1221634425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51114 (or 51109 counting only the distinct ones).

The product of its digits is 11520, while the sum is 30.

The square root of 1221634425 is about 34951.8872880993. The cubic root of 1221634425 is about 1069.0066843539.

Adding to 1221634425 its reverse (5244361221), we get a palindrome (6465995646).

The spelling of 1221634425 in words is "one billion, two hundred twenty-one million, six hundred thirty-four thousand, four hundred twenty-five".