919987261 has 2 divisors, whose sum is σ = 919987262. Its totient is φ = 919987260.

The previous prime is 919987247. The next prime is 919987291. The reversal of 919987261 is 162789919.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 918999225 + 988036 = 30315^2 + 994^2 .

It is an emirp because it is prime and its reverse (162789919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 919987261 - 2¹⁵ = 919954493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 919987199 and 919987208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (919987231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459993630 + 459993631.

It is an arithmetic number, because the mean of its divisors is an integer number (459993631).

Almost surely, 2^919987261 is an apocalyptic number.

It is an amenable number.

919987261 is a deficient number, since it is larger than the sum of its proper divisors (1).

919987261 is an equidigital number, since it uses as much as digits as its factorization.

919987261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 52.

The square root of 919987261 is about 30331.2917792830. The cubic root of 919987261 is about 972.5843371369.

The spelling of 919987261 in words is "nine hundred nineteen million, nine hundred eighty-seven thousand, two hundred sixty-one".