28961913123 has 240 divisors, whose sum is σ = 55098869760. Its totient is φ = 14981241600.

The previous prime is 28961913089. The next prime is 28961913131. The reversal of 28961913123 is 32131916982.

It is a happy number.

28961913123 is a `hidden beast` number, since 2 + 8 + 9 + 619 + 1 + 3 + 1 + 23 = 666.

It is a Cunningham number, because it is equal to 170182²-1.

It is not a de Polignac number, because 28961913123 - 2¹³ = 28961904931 is a prime.

It is a super-2 number, since 2×28961913123² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28961913163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 151632958 + ... + 151633148.

It is an arithmetic number, because the mean of its divisors is an integer number (229578624).

Almost surely, 2^28961913123 is an apocalyptic number.

28961913123 is a deficient number, since it is larger than the sum of its proper divisors (26136956637).

28961913123 is a wasteful number, since it uses less digits than its factorization.

28961913123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312 (or 290 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The spelling of 28961913123 in words is "twenty-eight billion, nine hundred sixty-one million, nine hundred thirteen thousand, one hundred twenty-three".