1221015 has 8 divisors (see below), whose sum is σ = 1953648. Its totient is φ = 651200.

The previous prime is 1220993. The next prime is 1221019. The reversal of 1221015 is 5101221.

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

It is not a de Polignac number, because 1221015 - 2⁵ = 1220983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221019) 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, 40686 + ... + 40715.

It is an arithmetic number, because the mean of its divisors is an integer number (244206).

2^1221015 is an apocalyptic number.

1221015 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221015 is a deficient number, since it is larger than the sum of its proper divisors (732633).

1221015 is an equidigital number, since it uses as much as digits as its factorization.

1221015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81409.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 1221015 is about 1104.9954751039. The cubic root of 1221015 is about 106.8825975243.

Adding to 1221015 its reverse (5101221), we get a palindrome (6322236).

The spelling of 1221015 in words is "one million, two hundred twenty-one thousand, fifteen".