19766540 has 24 divisors (see below), whose sum is σ = 41640480. Its totient is φ = 7881728.

The previous prime is 19766519. The next prime is 19766543. The reversal of 19766540 is 4566791.

It is a super-2 number, since 2×19766540² = 781432207143200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19766494 and 19766503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19766543) 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, 5804 + ... + 8556.

It is an arithmetic number, because the mean of its divisors is an integer number (1735020).

Almost surely, 2^19766540 is an apocalyptic number.

19766540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19766540 is an abundant number, since it is smaller than the sum of its proper divisors (21873940).

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

19766540 is a wasteful number, since it uses less digits than its factorization.

19766540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3121 (or 3119 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 19766540 is about 4445.9577145987. The cubic root of 19766540 is about 270.3814453090.

The spelling of 19766540 in words is "nineteen million, seven hundred sixty-six thousand, five hundred forty".