125559809 has 16 divisors (see below), whose sum is σ = 136745280. Its totient is φ = 114903360.

The previous prime is 125559803. The next prime is 125559823. The reversal of 125559809 is 908955521.

It is a cyclic number.

It is not a de Polignac number, because 125559809 - 2¹² = 125555713 is a prime.

It is a super-2 number, since 2×125559809² = 31530531272232962, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 125559809.

It is not an unprimeable number, because it can be changed into a prime (125559803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66539 + ... + 68399.

It is an arithmetic number, because the mean of its divisors is an integer number (8546580).

Almost surely, 2^125559809 is an apocalyptic number.

125559809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

125559809 is a deficient number, since it is larger than the sum of its proper divisors (11185471).

125559809 is a wasteful number, since it uses less digits than its factorization.

125559809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000.

The product of its (nonzero) digits is 162000, while the sum is 44.

The square root of 125559809 is about 11205.3473395518. The cubic root of 125559809 is about 500.7453005023.

The spelling of 125559809 in words is "one hundred twenty-five million, five hundred fifty-nine thousand, eight hundred nine".