1211421225 has 24 divisors (see below), whose sum is σ = 2289010240. Its totient is φ = 553792320.

The previous prime is 1211421199. The next prime is 1211421227. The reversal of 1211421225 is 5221241121.

It is not a de Polignac number, because 1211421225 - 2⁹ = 1211420713 is a prime.

It is a super-3 number, since 3×1211421225³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1211421227) 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, 1153210 + ... + 1154259.

Almost surely, 2^1211421225 is an apocalyptic number.

1211421225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211421225 is a deficient number, since it is larger than the sum of its proper divisors (1077589015).

1211421225 is a wasteful number, since it uses less digits than its factorization.

1211421225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2307489 (or 2307484 counting only the distinct ones).

The product of its digits is 320, while the sum is 21.

The square root of 1211421225 is about 34805.4769397002. The cubic root of 1211421225 is about 1066.0192802875.

Adding to 1211421225 its reverse (5221241121), we get a palindrome (6432662346).

The spelling of 1211421225 in words is "one billion, two hundred eleven million, four hundred twenty-one thousand, two hundred twenty-five".