1985509693440 has 576 divisors, whose sum is σ = 8469475560000. Its totient is φ = 418918957056.

The previous prime is 1985509693429. The next prime is 1985509693451. The reversal of 1985509693440 is 443969055891.

1985509693440 is a `hidden beast` number, since 1 + 9 + 8 + 550 + 9 + 6 + 9 + 34 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (1985509693429) and next prime (1985509693451).

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8268186 + ... + 8504934.

It is an arithmetic number, because the mean of its divisors is an integer number (14703950625).

Almost surely, 2^{1985509693440} is an apocalyptic number.

1985509693440 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 1985509693440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4234737780000).

1985509693440 is an abundant number, since it is smaller than the sum of its proper divisors (6483965866560).

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

1985509693440 is a wasteful number, since it uses less digits than its factorization.

1985509693440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236802 (or 236779 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 63.

The spelling of 1985509693440 in words is "one trillion, nine hundred eighty-five billion, five hundred nine million, six hundred ninety-three thousand, four hundred forty".