20718254149640 has 64 divisors (see below), whose sum is σ = 49309198243200. Its totient is φ = 7818395346432.

The previous prime is 20718254149597. The next prime is 20718254149657. The reversal of 20718254149640 is 4694145281702.

It is a happy number.

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, 154178330 + ... + 154312649.

It is an arithmetic number, because the mean of its divisors is an integer number (770456222550).

Almost surely, 2^{20718254149640} is an apocalyptic number.

20718254149640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20718254149640 is an abundant number, since it is smaller than the sum of its proper divisors (28590944093560).

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

20718254149640 is a wasteful number, since it uses less digits than its factorization.

20718254149640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308491086 (or 308491082 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 53.

The spelling of 20718254149640 in words is "twenty trillion, seven hundred eighteen billion, two hundred fifty-four million, one hundred forty-nine thousand, six hundred forty".