1221515141 has 8 divisors (see below), whose sum is σ = 1522928064. Its totient is φ = 951829920.

The previous prime is 1221515137. The next prime is 1221515167. The reversal of 1221515141 is 1415151221.

It is a happy number.

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 1221515141 - 2² = 1221515137 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221515171) 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, 7931840 + ... + 7931993.

It is an arithmetic number, because the mean of its divisors is an integer number (190366008).

Almost surely, 2^1221515141 is an apocalyptic number.

1221515141 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221515141 is a deficient number, since it is larger than the sum of its proper divisors (301412923).

1221515141 is a wasteful number, since it uses less digits than its factorization.

1221515141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15863851.

The product of its digits is 400, while the sum is 23.

The square root of 1221515141 is about 34950.1808435951. The cubic root of 1221515141 is about 1068.9718895628.

Adding to 1221515141 its reverse (1415151221), we get a palindrome (2636666362).

The spelling of 1221515141 in words is "one billion, two hundred twenty-one million, five hundred fifteen thousand, one hundred forty-one".