1668572501 has 2 divisors, whose sum is σ = 1668572502. Its totient is φ = 1668572500.

The previous prime is 1668572497. The next prime is 1668572519. The reversal of 1668572501 is 1052758661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1359691876 + 308880625 = 36874^2 + 17575^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668572501 - 2² = 1668572497 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1668572561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834286250 + 834286251.

It is an arithmetic number, because the mean of its divisors is an integer number (834286251).

Almost surely, 2^1668572501 is an apocalyptic number.

It is an amenable number.

1668572501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668572501 is an equidigital number, since it uses as much as digits as its factorization.

1668572501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 41.

The square root of 1668572501 is about 40848.1639856677. The cubic root of 1668572501 is about 1186.0828526398.

The spelling of 1668572501 in words is "one billion, six hundred sixty-eight million, five hundred seventy-two thousand, five hundred one".