919969561 has 15 divisors (see below), whose sum is σ = 1074970581. Its totient is φ = 787271436.

The previous prime is 919969513. The next prime is 919969573. The reversal of 919969561 is 165969919.

The square root of 919969561 is 30331.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 919969561 - 2¹¹ = 919967513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (919969861) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1485910 + ... + 1486528.

Almost surely, 2^919969561 is an apocalyptic number.

919969561 is the 30331-st square number.

919969561 is the 15166-th centered octagonal number.

It is an amenable number.

919969561 is a deficient number, since it is larger than the sum of its proper divisors (155001020).

919969561 is an frugal number, since it uses more digits than its factorization.

919969561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266 (or 626 counting only the distinct ones).

The product of its digits is 1180980, while the sum is 55.

The cubic root of 919969561 is about 972.5780997849.

The spelling of 919969561 in words is "nine hundred nineteen million, nine hundred sixty-nine thousand, five hundred sixty-one".