123675781 has 4 divisors (see below), whose sum is σ = 123725152. Its totient is φ = 123626412.

The previous prime is 123675767. The next prime is 123675787. The reversal of 123675781 is 187576321.

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, and also an emirpimes, since its reverse is a distinct semiprime: 187576321 = 29 ⋅6468149.

It is a cyclic number.

It is not a de Polignac number, because 123675781 - 2¹³ = 123667589 is a prime.

It is a super-2 number, since 2×123675781² = 30591397611919922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123675787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20715 + ... + 26008.

It is an arithmetic number, because the mean of its divisors is an integer number (30931288).

Almost surely, 2^123675781 is an apocalyptic number.

It is an amenable number.

123675781 is a deficient number, since it is larger than the sum of its proper divisors (49371).

123675781 is an equidigital number, since it uses as much as digits as its factorization.

123675781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49370.

The product of its digits is 70560, while the sum is 40.

The square root of 123675781 is about 11120.9613343452. The cubic root of 123675781 is about 498.2281028451.

The spelling of 123675781 in words is "one hundred twenty-three million, six hundred seventy-five thousand, seven hundred eighty-one".