1215887399645 has 8 divisors (see below), whose sum is σ = 1467498781656. Its totient is φ = 967087318336.

The previous prime is 1215887399633. The next prime is 1215887399647. The reversal of 1215887399645 is 5469937885121.

It can be written as a sum of positive squares in 4 ways, for example, as 43002731641 + 1172884668004 = 207371^2 + 1082998^2 .

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 1215887399645 - 2¹⁴ = 1215887383261 is a prime.

It is a super-2 number, since 2×1215887399645² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215887399647) 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, 702824222 + ... + 702825951.

It is an arithmetic number, because the mean of its divisors is an integer number (183437347707).

Almost surely, 2^{1215887399645} is an apocalyptic number.

It is an amenable number.

1215887399645 is a deficient number, since it is larger than the sum of its proper divisors (251611382011).

1215887399645 is a wasteful number, since it uses less digits than its factorization.

1215887399645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1405650351.

The product of its digits is 130636800, while the sum is 68.

The spelling of 1215887399645 in words is "one trillion, two hundred fifteen billion, eight hundred eighty-seven million, three hundred ninety-nine thousand, six hundred forty-five".