19729940 has 12 divisors (see below), whose sum is σ = 41432916. Its totient is φ = 7891968.

The previous prime is 19729933. The next prime is 19729943. The reversal of 19729940 is 4992791.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4999696 + 14730244 = 2236^2 + 3838^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19729943) 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, 493229 + ... + 493268.

It is an arithmetic number, because the mean of its divisors is an integer number (3452743).

Almost surely, 2^19729940 is an apocalyptic number.

19729940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19729940 is an abundant number, since it is smaller than the sum of its proper divisors (21702976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19729940 is a wasteful number, since it uses less digits than its factorization.

19729940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986506 (or 986504 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 19729940 is about 4441.8397089494. The cubic root of 19729940 is about 270.2144615236.

The spelling of 19729940 in words is "nineteen million, seven hundred twenty-nine thousand, nine hundred forty".