19749087540 has 1152 divisors, whose sum is σ = 84536524800. Its totient is φ = 3613040640.

The previous prime is 19749087539. The next prime is 19749087541. The reversal of 19749087540 is 4578094791.

19749087540 is a `hidden beast` number, since 1 + 9 + 7 + 4 + 90 + 8 + 7 + 540 = 666.

It is an interprime number because it is at equal distance from previous prime (19749087539) and next prime (19749087541).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19749087541) by changing a digit.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 221899816 + ... + 221899904.

It is an arithmetic number, because the mean of its divisors is an integer number (73382400).

Almost surely, 2^19749087540 is an apocalyptic number.

19749087540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19749087540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42268262400).

19749087540 is an abundant number, since it is smaller than the sum of its proper divisors (64787437260).

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

19749087540 is a wasteful number, since it uses less digits than its factorization.

19749087540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The spelling of 19749087540 in words is "nineteen billion, seven hundred forty-nine million, eighty-seven thousand, five hundred forty".