124540021 has 4 divisors (see below), whose sum is σ = 125682700. Its totient is φ = 123397344.

The previous prime is 124540019. The next prime is 124540033. The reversal of 124540021 is 120045421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120045421 = 193 ⋅621997.

It can be written as a sum of positive squares in 2 ways, for example, as 50339025 + 74200996 = 7095^2 + 8614^2 .

It is a cyclic number.

It is not a de Polignac number, because 124540021 - 2¹ = 124540019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (124540061) 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, 571176 + ... + 571393.

It is an arithmetic number, because the mean of its divisors is an integer number (31420675).

Almost surely, 2^124540021 is an apocalyptic number.

It is an amenable number.

124540021 is a deficient number, since it is larger than the sum of its proper divisors (1142679).

124540021 is a wasteful number, since it uses less digits than its factorization.

124540021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1142678.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 124540021 is about 11159.7500420036. The cubic root of 124540021 is about 499.3859408381.

Adding to 124540021 its reverse (120045421), we get a palindrome (244585442).

It can be divided in two parts, 1245400 and 21, that added together give a palindrome (1245421).

The spelling of 124540021 in words is "one hundred twenty-four million, five hundred forty thousand, twenty-one".