123445651561 has 16 divisors (see below), whose sum is σ = 128470795200. Its totient is φ = 118538475328.

The previous prime is 123445651559. The next prime is 123445651573. The reversal of 123445651561 is 165156544321.

It is a cyclic number.

It is not a de Polignac number, because 123445651561 - 2¹ = 123445651559 is a prime.

It is a super-3 number, since 3×123445651561³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123445651061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 622875 + ... + 796783.

It is an arithmetic number, because the mean of its divisors is an integer number (8029424700).

Almost surely, 2^123445651561 is an apocalyptic number.

It is an amenable number.

123445651561 is a deficient number, since it is larger than the sum of its proper divisors (5025143639).

123445651561 is a wasteful number, since it uses less digits than its factorization.

123445651561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174248.

The product of its digits is 432000, while the sum is 43.

The spelling of 123445651561 in words is "one hundred twenty-three billion, four hundred forty-five million, six hundred fifty-one thousand, five hundred sixty-one".