1221530253 has 8 divisors (see below), whose sum is σ = 1699520448. Its totient is φ = 778946784.

The previous prime is 1221530249. The next prime is 1221530279. The reversal of 1221530253 is 3520351221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221530253 - 2² = 1221530249 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221530203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8851600 + ... + 8851737.

It is an arithmetic number, because the mean of its divisors is an integer number (212440056).

Almost surely, 2^1221530253 is an apocalyptic number.

It is an amenable number.

1221530253 is a deficient number, since it is larger than the sum of its proper divisors (477990195).

1221530253 is a wasteful number, since it uses less digits than its factorization.

1221530253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17703363.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 1221530253 is about 34950.3970363714. The cubic root of 1221530253 is about 1068.9762978139.

Adding to 1221530253 its reverse (3520351221), we get a palindrome (4741881474).

It can be divided in two parts, 122 and 1530253, that added together give a triangular number (1530375 = T₁₇₄₉).

The spelling of 1221530253 in words is "one billion, two hundred twenty-one million, five hundred thirty thousand, two hundred fifty-three".