49991569 has 4 divisors (see below), whose sum is σ = 50507044. Its totient is φ = 49476096.

The previous prime is 49991549. The next prime is 49991609. The reversal of 49991569 is 96519994.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96519994 = 2 ⋅48259997.

It can be written as a sum of positive squares in 2 ways, for example, as 7219969 + 42771600 = 2687^2 + 6540^2 .

It is a cyclic number.

It is not a de Polignac number, because 49991569 - 2⁵ = 49991537 is a prime.

It is a super-4 number, since 4×49991569⁴ (a number of 32 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (49991549) 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, 257592 + ... + 257785.

It is an arithmetic number, because the mean of its divisors is an integer number (12626761).

Almost surely, 2^49991569 is an apocalyptic number.

It is an amenable number.

49991569 is a deficient number, since it is larger than the sum of its proper divisors (515475).

49991569 is an equidigital number, since it uses as much as digits as its factorization.

49991569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515474.

The product of its digits is 787320, while the sum is 52.

The square root of 49991569 is about 7070.4716250049. The cubic root of 49991569 is about 368.3824419870.

The spelling of 49991569 in words is "forty-nine million, nine hundred ninety-one thousand, five hundred sixty-nine".