19797540 has 48 divisors (see below), whose sum is σ = 63353472. Its totient is φ = 4525056.

The previous prime is 19797539. The next prime is 19797551. The reversal of 19797540 is 4579791.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 19797492 and 19797501.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23149 + ... + 23988.

It is an arithmetic number, because the mean of its divisors is an integer number (1319864).

Almost surely, 2^19797540 is an apocalyptic number.

19797540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19797540 is an abundant number, since it is smaller than the sum of its proper divisors (43555932).

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

19797540 is a wasteful number, since it uses less digits than its factorization.

19797540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47156 (or 47154 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 42.

The square root of 19797540 is about 4449.4426617274. The cubic root of 19797540 is about 270.5227185054.

The spelling of 19797540 in words is "nineteen million, seven hundred ninety-seven thousand, five hundred forty".