1651016501561 has 4 divisors (see below), whose sum is σ = 1886876001792. Its totient is φ = 1415157001332.

The previous prime is 1651016501551. The next prime is 1651016501567. The reversal of 1651016501561 is 1651056101561.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-1651016501561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1651016501567) 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, 117929750105 + ... + 117929750118.

It is an arithmetic number, because the mean of its divisors is an integer number (471719000448).

Almost surely, 2^{1651016501561} is an apocalyptic number.

It is an amenable number.

1651016501561 is a deficient number, since it is larger than the sum of its proper divisors (235859500231).

1651016501561 is an equidigital number, since it uses as much as digits as its factorization.

1651016501561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235859500230.

The product of its (nonzero) digits is 27000, while the sum is 38.

The spelling of 1651016501561 in words is "one trillion, six hundred fifty-one billion, sixteen million, five hundred one thousand, five hundred sixty-one".