19861631 has 4 divisors (see below), whose sum is σ = 20907000. Its totient is φ = 18816264.

The previous prime is 19861613. The next prime is 19861649. The reversal of 19861631 is 13616891.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (19861613) and next prime (19861649).

It is a cyclic number.

It is not a de Polignac number, because 19861631 - 2¹⁴ = 19845247 is a prime.

It is a super-2 number, since 2×19861631² = 788968771960322, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 19861591 and 19861600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19861031) 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, 522656 + ... + 522693.

It is an arithmetic number, because the mean of its divisors is an integer number (5226750).

Almost surely, 2^19861631 is an apocalyptic number.

19861631 is a deficient number, since it is larger than the sum of its proper divisors (1045369).

19861631 is a wasteful number, since it uses less digits than its factorization.

19861631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1045368.

The product of its digits is 7776, while the sum is 35.

The square root of 19861631 is about 4456.6389802182. The cubic root of 19861631 is about 270.8143270502.

The spelling of 19861631 in words is "nineteen million, eight hundred sixty-one thousand, six hundred thirty-one".