1215250221 has 8 divisors (see below), whose sum is σ = 1644517984. Its totient is φ = 798074640.

The previous prime is 1215250217. The next prime is 1215250259. The reversal of 1215250221 is 1220525121.

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

It is not a de Polignac number, because 1215250221 - 2² = 1215250217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215250261) 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, 3022810 + ... + 3023211.

It is an arithmetic number, because the mean of its divisors is an integer number (205564748).

Almost surely, 2^1215250221 is an apocalyptic number.

It is an amenable number.

1215250221 is a deficient number, since it is larger than the sum of its proper divisors (429267763).

1215250221 is an equidigital number, since it uses as much as digits as its factorization.

1215250221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6046091.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 1215250221 is about 34860.4391968891. The cubic root of 1215250221 is about 1067.1412381215.

Adding to 1215250221 its reverse (1220525121), we get a palindrome (2435775342).

The spelling of 1215250221 in words is "one billion, two hundred fifteen million, two hundred fifty thousand, two hundred twenty-one".