1662130021 has 4 divisors (see below), whose sum is σ = 1707052492. Its totient is φ = 1617207552.

The previous prime is 1662130003. The next prime is 1662130031. The reversal of 1662130021 is 1200312661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1200312661 = 23 ⋅52187507.

It can be written as a sum of positive squares in 2 ways, for example, as 944640225 + 717489796 = 30735^2 + 26786^2 .

It is a cyclic number.

It is not a de Polignac number, because 1662130021 - 2⁹ = 1662129509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1662129974 and 1662130001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1662130031) 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, 22461180 + ... + 22461253.

It is an arithmetic number, because the mean of its divisors is an integer number (426763123).

Almost surely, 2^1662130021 is an apocalyptic number.

It is an amenable number.

1662130021 is a deficient number, since it is larger than the sum of its proper divisors (44922471).

1662130021 is an equidigital number, since it uses as much as digits as its factorization.

1662130021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44922470.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1662130021 is about 40769.2288497097. The cubic root of 1662130021 is about 1184.5543663120.

Adding to 1662130021 its reverse (1200312661), we get a palindrome (2862442682).

The spelling of 1662130021 in words is "one billion, six hundred sixty-two million, one hundred thirty thousand, twenty-one".