1642500121 has 4 divisors (see below), whose sum is σ = 1644426532. Its totient is φ = 1640573712.

The previous prime is 1642500113. The next prime is 1642500149. The reversal of 1642500121 is 1210052461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1210052461 = 10133 ⋅119417.

It can be written as a sum of positive squares in 2 ways, for example, as 535274496 + 1107225625 = 23136^2 + 33275^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642500121 - 2³ = 1642500113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1642500092 and 1642500101.

It is not an unprimeable number, because it can be changed into a prime (1642500721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 961926 + ... + 963631.

It is an arithmetic number, because the mean of its divisors is an integer number (411106633).

Almost surely, 2^1642500121 is an apocalyptic number.

It is an amenable number.

1642500121 is a deficient number, since it is larger than the sum of its proper divisors (1926411).

1642500121 is an equidigital number, since it uses as much as digits as its factorization.

1642500121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1926410.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1642500121 is about 40527.7697511225. The cubic root of 1642500121 is about 1179.8726571859.

Adding to 1642500121 its reverse (1210052461), we get a palindrome (2852552582).

The spelling of 1642500121 in words is "one billion, six hundred forty-two million, five hundred thousand, one hundred twenty-one".