1660121651 has 2 divisors, whose sum is σ = 1660121652. Its totient is φ = 1660121650.

The previous prime is 1660121647. The next prime is 1660121657. The reversal of 1660121651 is 1561210661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1660121651 - 2² = 1660121647 is a prime.

It is a super-2 number, since 2×1660121651² = 5512007792237931602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1660121657) 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 as a sum of consecutive naturals, namely, 830060825 + 830060826.

It is an arithmetic number, because the mean of its divisors is an integer number (830060826).

Almost surely, 2^1660121651 is an apocalyptic number.

1660121651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660121651 is an equidigital number, since it uses as much as digits as its factorization.

1660121651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 1660121651 is about 40744.5904507580. The cubic root of 1660121651 is about 1184.0770706599.

The spelling of 1660121651 in words is "one billion, six hundred sixty million, one hundred twenty-one thousand, six hundred fifty-one".