1215540973 has 2 divisors, whose sum is σ = 1215540974. Its totient is φ = 1215540972.

The previous prime is 1215540971. The next prime is 1215541013. The reversal of 1215540973 is 3790455121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 643231044 + 572309929 = 25362^2 + 23923^2 .

It is a cyclic number.

It is not a de Polignac number, because 1215540973 - 2¹ = 1215540971 is a prime.

Together with 1215540971, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1215540971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607770486 + 607770487.

It is an arithmetic number, because the mean of its divisors is an integer number (607770487).

Almost surely, 2^1215540973 is an apocalyptic number.

It is an amenable number.

1215540973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215540973 is an equidigital number, since it uses as much as digits as its factorization.

1215540973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 1215540973 is about 34864.6091760685. The cubic root of 1215540973 is about 1067.2263368396.

The spelling of 1215540973 in words is "one billion, two hundred fifteen million, five hundred forty thousand, nine hundred seventy-three".