19613381 has 4 divisors (see below), whose sum is σ = 19622592. Its totient is φ = 19604172.

The previous prime is 19613369. The next prime is 19613387. The reversal of 19613381 is 18331691.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18331691 = 7 ⋅2618813.

It is a cyclic number.

It is not a de Polignac number, because 19613381 - 2¹⁸ = 19351237 is a prime.

It is a super-2 number, since 2×19613381² = 769369428502322, 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 (19613387) 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, 410 + ... + 6276.

It is an arithmetic number, because the mean of its divisors is an integer number (4905648).

Almost surely, 2^19613381 is an apocalyptic number.

It is an amenable number.

19613381 is a deficient number, since it is larger than the sum of its proper divisors (9211).

19613381 is an equidigital number, since it uses as much as digits as its factorization.

19613381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9210.

The product of its digits is 3888, while the sum is 32.

The square root of 19613381 is about 4428.6996962991. The cubic root of 19613381 is about 269.6812929001.

The spelling of 19613381 in words is "nineteen million, six hundred thirteen thousand, three hundred eighty-one".