1215021045 has 16 divisors (see below), whose sum is σ = 2221752960. Its totient is φ = 555438144.

The previous prime is 1215021013. The next prime is 1215021077. The reversal of 1215021045 is 5401205121.

It is an interprime number because it is at equal distance from previous prime (1215021013) and next prime (1215021077).

It is not a de Polignac number, because 1215021045 - 2⁵ = 1215021013 is a prime.

It is a super-2 number, since 2×1215021045² = 2952552279585784050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5785710 + ... + 5785919.

It is an arithmetic number, because the mean of its divisors is an integer number (138859560).

Almost surely, 2^1215021045 is an apocalyptic number.

1215021045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1215021045 is a deficient number, since it is larger than the sum of its proper divisors (1006731915).

1215021045 is a wasteful number, since it uses less digits than its factorization.

1215021045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11571644.

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

The square root of 1215021045 is about 34857.1519920948. The cubic root of 1215021045 is about 1067.0741522019.

Adding to 1215021045 its reverse (5401205121), we get a palindrome (6616226166).

The spelling of 1215021045 in words is "one billion, two hundred fifteen million, twenty-one thousand, forty-five".