19945631 has 4 divisors (see below), whose sum is σ = 19962264. Its totient is φ = 19929000.

The previous prime is 19945621. The next prime is 19945691. The reversal of 19945631 is 13654991.

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 19945631 - 2²² = 15751327 is a prime.

It is a super-2 number, since 2×19945631² = 795656391976322, 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 (19945621) 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, 6365 + ... + 8966.

It is an arithmetic number, because the mean of its divisors is an integer number (4990566).

Almost surely, 2^19945631 is an apocalyptic number.

19945631 is a deficient number, since it is larger than the sum of its proper divisors (16633).

19945631 is a wasteful number, since it uses less digits than its factorization.

19945631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16632.

The product of its digits is 29160, while the sum is 38.

The square root of 19945631 is about 4466.0531792624. The cubic root of 19945631 is about 271.1955714870.

The spelling of 19945631 in words is "nineteen million, nine hundred forty-five thousand, six hundred thirty-one".