1221134021 has 8 divisors (see below), whose sum is σ = 1293978240. Its totient is φ = 1148402368.

The previous prime is 1221134017. The next prime is 1221134029. The reversal of 1221134021 is 1204311221.

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 1221134021 - 2² = 1221134017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221134029) 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, 5261 + ... + 49698.

It is an arithmetic number, because the mean of its divisors is an integer number (161747280).

Almost surely, 2^1221134021 is an apocalyptic number.

It is an amenable number.

1221134021 is a deficient number, since it is larger than the sum of its proper divisors (72844219).

1221134021 is a wasteful number, since it uses less digits than its factorization.

1221134021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56283.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1221134021 is about 34944.7280859359. The cubic root of 1221134021 is about 1068.8607027993.

Adding to 1221134021 its reverse (1204311221), we get a palindrome (2425445242).

The spelling of 1221134021 in words is "one billion, two hundred twenty-one million, one hundred thirty-four thousand, twenty-one".