101661840 has 240 divisors, whose sum is σ = 407616768. Its totient is φ = 22201344.

The previous prime is 101661827. The next prime is 101661869. The reversal of 101661840 is 48166101.

101661840 is a `hidden beast` number, since 1 + 0 + 1 + 6 + 618 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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, 115482 + ... + 116358.

Almost surely, 2^101661840 is an apocalyptic number.

101661840 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 101661840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203808384).

101661840 is an abundant number, since it is smaller than the sum of its proper divisors (305954928).

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

101661840 is a wasteful number, since it uses less digits than its factorization.

101661840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 926 (or 917 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 101661840 is about 10082.7496249783. The cubic root of 101661840 is about 466.7159630464.

The spelling of 101661840 in words is "one hundred one million, six hundred sixty-one thousand, eight hundred forty".