19915240 has 32 divisors (see below), whose sum is σ = 46759680. Its totient is φ = 7619392.

The previous prime is 19915223. The next prime is 19915243. The reversal of 19915240 is 4251991.

It is not an unprimeable number, because it can be changed into a prime (19915243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9904 + ... + 11743.

It is an arithmetic number, because the mean of its divisors is an integer number (1461240).

Almost surely, 2^19915240 is an apocalyptic number.

19915240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19915240 is an abundant number, since it is smaller than the sum of its proper divisors (26844440).

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

19915240 is a wasteful number, since it uses less digits than its factorization.

19915240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21681 (or 21677 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 19915240 is about 4462.6494372738. The cubic root of 19915240 is about 271.0577619553.

The spelling of 19915240 in words is "nineteen million, nine hundred fifteen thousand, two hundred forty".