18937813 has 8 divisors (see below), whose sum is σ = 21107520. Its totient is φ = 16885440.

The previous prime is 18937799. The next prime is 18937817. The reversal of 18937813 is 31873981.

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 18937813 - 2⁹ = 18937301 is a prime.

It is a super-2 number, since 2×18937813² = 717281522445938, 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 (18937817) 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, 28993 + ... + 29638.

It is an arithmetic number, because the mean of its divisors is an integer number (2638440).

Almost surely, 2^18937813 is an apocalyptic number.

It is an amenable number.

18937813 is a deficient number, since it is larger than the sum of its proper divisors (2169707).

18937813 is a wasteful number, since it uses less digits than its factorization.

18937813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58667.

The product of its digits is 36288, while the sum is 40.

The square root of 18937813 is about 4351.7597589941. The cubic root of 18937813 is about 266.5487240587.

The spelling of 18937813 in words is "eighteen million, nine hundred thirty-seven thousand, eight hundred thirteen".