915961987 has 2 divisors, whose sum is σ = 915961988. Its totient is φ = 915961986.

The previous prime is 915961967. The next prime is 915961997. The reversal of 915961987 is 789169519.

It is a strong prime.

It is an emirp because it is prime and its reverse (789169519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 915961987 - 2²³ = 907573379 is a prime.

It is not a weakly prime, because it can be changed into another prime (915961957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 457980993 + 457980994.

It is an arithmetic number, because the mean of its divisors is an integer number (457980994).

Almost surely, 2^915961987 is an apocalyptic number.

915961987 is a deficient number, since it is larger than the sum of its proper divisors (1).

915961987 is an equidigital number, since it uses as much as digits as its factorization.

915961987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1224720, while the sum is 55.

The square root of 915961987 is about 30264.8639018912. The cubic root of 915961987 is about 971.1637949712.

The spelling of 915961987 in words is "nine hundred fifteen million, nine hundred sixty-one thousand, nine hundred eighty-seven".