1221511423 has 8 divisors (see below), whose sum is σ = 1336193280. Its totient is φ = 1107435480.

The previous prime is 1221511399. The next prime is 1221511429. The reversal of 1221511423 is 3241151221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221511423 - 2²⁹ = 684640511 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221511394 and 1221511403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221511429) 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, 147253 + ... + 155326.

It is an arithmetic number, because the mean of its divisors is an integer number (167024160).

Almost surely, 2^1221511423 is an apocalyptic number.

1221511423 is a deficient number, since it is larger than the sum of its proper divisors (114681857).

1221511423 is a wasteful number, since it uses less digits than its factorization.

1221511423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302957.

The product of its digits is 480, while the sum is 22.

The square root of 1221511423 is about 34950.1276535580. The cubic root of 1221511423 is about 1068.9708049967.

Adding to 1221511423 its reverse (3241151221), we get a palindrome (4462662644).

The spelling of 1221511423 in words is "one billion, two hundred twenty-one million, five hundred eleven thousand, four hundred twenty-three".