1215965541 has 32 divisors (see below), whose sum is σ = 1950658560. Its totient is φ = 658715904.

The previous prime is 1215965537. The next prime is 1215965549. The reversal of 1215965541 is 1455695121.

It is not a de Polignac number, because 1215965541 - 2² = 1215965537 is a prime.

It is a super-4 number, since 4×1215965541⁴ (a number of 37 digits) contains 4444 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1215965541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215965549) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43440 + ... + 65718.

It is an arithmetic number, because the mean of its divisors is an integer number (60958080).

Almost surely, 2^1215965541 is an apocalyptic number.

It is an amenable number.

1215965541 is a deficient number, since it is larger than the sum of its proper divisors (734693019).

1215965541 is a wasteful number, since it uses less digits than its factorization.

1215965541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22425.

The product of its digits is 54000, while the sum is 39.

The square root of 1215965541 is about 34870.6974550266. The cubic root of 1215965541 is about 1067.3505771071.

The spelling of 1215965541 in words is "one billion, two hundred fifteen million, nine hundred sixty-five thousand, five hundred forty-one".