19662381 has 6 divisors (see below), whose sum is σ = 28401230. Its totient is φ = 13108248.

The previous prime is 19662343. The next prime is 19662407. The reversal of 19662381 is 18326691.

It can be written as a sum of positive squares in only one way, i.e., 19660356 + 2025 = 4434^2 + 45^2 .

It is not a de Polignac number, because 19662381 - 2⁶ = 19662317 is a prime.

It is a super-2 number, since 2×19662381² = 773218453178322, 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 (19662301) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1092346 + ... + 1092363.

Almost surely, 2^19662381 is an apocalyptic number.

It is an amenable number.

19662381 is a deficient number, since it is larger than the sum of its proper divisors (8738849).

19662381 is a wasteful number, since it uses less digits than its factorization.

19662381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184715 (or 2184712 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 19662381 is about 4434.2283432408. The cubic root of 19662381 is about 269.9056872244.

The spelling of 19662381 in words is "nineteen million, six hundred sixty-two thousand, three hundred eighty-one".