18723961 has 8 divisors (see below), whose sum is σ = 19381824. Its totient is φ = 18074160.

The previous prime is 18723959. The next prime is 18723967. The reversal of 18723961 is 16932781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18723961 - 2¹ = 18723959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18723961.

It is not an unprimeable number, because it can be changed into a prime (18723967) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2916 + ... + 6778.

It is an arithmetic number, because the mean of its divisors is an integer number (2422728).

Almost surely, 2^18723961 is an apocalyptic number.

It is an amenable number.

18723961 is a deficient number, since it is larger than the sum of its proper divisors (657863).

18723961 is a wasteful number, since it uses less digits than its factorization.

18723961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4031.

The product of its digits is 18144, while the sum is 37.

The square root of 18723961 is about 4327.1192495701. The cubic root of 18723961 is about 265.5416050267.

The spelling of 18723961 in words is "eighteen million, seven hundred twenty-three thousand, nine hundred sixty-one".