19690391 has 8 divisors (see below), whose sum is σ = 23279520. Its totient is φ = 16295328.

The previous prime is 19690387. The next prime is 19690393. The reversal of 19690391 is 19309691.

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

It is not a de Polignac number, because 19690391 - 2² = 19690387 is a prime.

It is a super-2 number, since 2×19690391² = 775422995465762, 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 (19690393) 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, 48296 + ... + 48701.

It is an arithmetic number, because the mean of its divisors is an integer number (2909940).

Almost surely, 2^19690391 is an apocalyptic number.

19690391 is a deficient number, since it is larger than the sum of its proper divisors (3589129).

19690391 is an equidigital number, since it uses as much as digits as its factorization.

19690391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97033.

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 19690391 is about 4437.3856041593. The cubic root of 19690391 is about 270.0337909240.

The spelling of 19690391 in words is "nineteen million, six hundred ninety thousand, three hundred ninety-one".