1660625021 has 8 divisors (see below), whose sum is σ = 1841289888. Its totient is φ = 1484910000.

The previous prime is 1660625011. The next prime is 1660625117. The reversal of 1660625021 is 1205260661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1660625021 - 2¹⁸ = 1660362877 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 (1660625011) 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 7 ways as a sum of consecutive naturals, for example, 1236755 + ... + 1238096.

It is an arithmetic number, because the mean of its divisors is an integer number (230161236).

Almost surely, 2^1660625021 is an apocalyptic number.

1660625021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1660625021 is a deficient number, since it is larger than the sum of its proper divisors (180664867).

1660625021 is a wasteful number, since it uses less digits than its factorization.

1660625021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2474923.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1660625021 is about 40750.7671216138. The cubic root of 1660625021 is about 1184.1967343090.

Adding to 1660625021 its reverse (1205260661), we get a palindrome (2865885682).

The spelling of 1660625021 in words is "one billion, six hundred sixty million, six hundred twenty-five thousand, twenty-one".