1215545972 has 12 divisors (see below), whose sum is σ = 2146031076. Its totient is φ = 602394240.

The previous prime is 1215545971. The next prime is 1215545999. The reversal of 1215545972 is 2795455121.

It can be written as a sum of positive squares in 2 ways, for example, as 73376356 + 1142169616 = 8566^2 + 33796^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215545971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1344179 + ... + 1345082.

It is an arithmetic number, because the mean of its divisors is an integer number (178835923).

Almost surely, 2^1215545972 is an apocalyptic number.

It is an amenable number.

1215545972 is a deficient number, since it is larger than the sum of its proper divisors (930485104).

1215545972 is a wasteful number, since it uses less digits than its factorization.

1215545972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689378 (or 2689376 counting only the distinct ones).

The product of its digits is 126000, while the sum is 41.

The square root of 1215545972 is about 34864.6808676058. The cubic root of 1215545972 is about 1067.2277998527.

The spelling of 1215545972 in words is "one billion, two hundred fifteen million, five hundred forty-five thousand, nine hundred seventy-two".