124809981 has 4 divisors (see below), whose sum is σ = 166413312. Its totient is φ = 83206652.

The previous prime is 124809961. The next prime is 124809989. The reversal of 124809981 is 189908421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 189908421 = 3 ⋅63302807.

It is a cyclic number.

It is not a de Polignac number, because 124809981 - 2¹¹ = 124807933 is a prime.

It is a super-2 number, since 2×124809981² = 31155062714440722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (124809989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20801661 + ... + 20801666.

It is an arithmetic number, because the mean of its divisors is an integer number (41603328).

Almost surely, 2^124809981 is an apocalyptic number.

It is an amenable number.

124809981 is a deficient number, since it is larger than the sum of its proper divisors (41603331).

124809981 is an equidigital number, since it uses as much as digits as its factorization.

124809981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41603330.

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 124809981 is about 11171.8387474936. The cubic root of 124809981 is about 499.7465128436.

The spelling of 124809981 in words is "one hundred twenty-four million, eight hundred nine thousand, nine hundred eighty-one".