123800891 has 4 divisors (see below), whose sum is σ = 125292552. Its totient is φ = 122309232.

The previous prime is 123800861. The next prime is 123800893. The reversal of 123800891 is 198008321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123800891 - 2¹⁰ = 123799867 is a prime.

It is a super-2 number, since 2×123800891² = 30653321224787762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123800893) 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, 745706 + ... + 745871.

It is an arithmetic number, because the mean of its divisors is an integer number (31323138).

Almost surely, 2^123800891 is an apocalyptic number.

123800891 is a deficient number, since it is larger than the sum of its proper divisors (1491661).

123800891 is an equidigital number, since it uses as much as digits as its factorization.

123800891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1491660.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 123800891 is about 11126.5848758727. The cubic root of 123800891 is about 498.3960481790.

The spelling of 123800891 in words is "one hundred twenty-three million, eight hundred thousand, eight hundred ninety-one".