1651066561 has 4 divisors (see below), whose sum is σ = 1679050800. Its totient is φ = 1623082324.

The previous prime is 1651066553. The next prime is 1651066591. The reversal of 1651066561 is 1656601561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1651066561 - 2³ = 1651066553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1651066561.

It is not an unprimeable number, because it can be changed into a prime (1651066511) 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, 13992031 + ... + 13992148.

It is an arithmetic number, because the mean of its divisors is an integer number (419762700).

Almost surely, 2^1651066561 is an apocalyptic number.

It is an amenable number.

1651066561 is a deficient number, since it is larger than the sum of its proper divisors (27984239).

1651066561 is an equidigital number, since it uses as much as digits as its factorization.

1651066561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27984238.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 1651066561 is about 40633.3183606754. The cubic root of 1651066561 is about 1181.9203054463.

The spelling of 1651066561 in words is "one billion, six hundred fifty-one million, sixty-six thousand, five hundred sixty-one".