19980631 has 4 divisors (see below), whose sum is σ = 21797064. Its totient is φ = 18164200.

The previous prime is 19980563. The next prime is 19980637. The reversal of 19980631 is 13608991.

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 19980631 - 2⁷ = 19980503 is a prime.

It is a super-2 number, since 2×19980631² = 798451230316322, 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 (19980637) 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, 908200 + ... + 908221.

It is an arithmetic number, because the mean of its divisors is an integer number (5449266).

Almost surely, 2^19980631 is an apocalyptic number.

19980631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19980631 is a deficient number, since it is larger than the sum of its proper divisors (1816433).

19980631 is a wasteful number, since it uses less digits than its factorization.

19980631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1816432.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 19980631 is about 4469.9699104133. The cubic root of 19980631 is about 271.3541074325.

The spelling of 19980631 in words is "nineteen million, nine hundred eighty thousand, six hundred thirty-one".