1205115021 has 24 divisors (see below), whose sum is σ = 1925726400. Its totient is φ = 720081600.

The previous prime is 1205115011. The next prime is 1205115029.

1205115021 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1205115021 - 2¹⁸ = 1204852877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1205114985 and 1205115003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205115029) 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, 78696 + ... + 92753.

It is an arithmetic number, because the mean of its divisors is an integer number (80238600).

Almost surely, 2^1205115021 is an apocalyptic number.

1205115021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1205115021 is a deficient number, since it is larger than the sum of its proper divisors (720611379).

1205115021 is a wasteful number, since it uses less digits than its factorization.

1205115021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171537 (or 171534 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

The square root of 1205115021 is about 34714.7666130712. The cubic root of 1205115021 is about 1064.1662958862.

It can be divided in two parts, 12051 and 15021, that added together give a palindrome (27072).

The spelling of 1205115021 in words is "one billion, two hundred five million, one hundred fifteen thousand, twenty-one".