102505840 has 40 divisors (see below), whose sum is σ = 246019968. Its totient is φ = 39678720.

The previous prime is 102505831. The next prime is 102505841. The reversal of 102505840 is 48505201.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102505841) 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, 18187 + ... + 23146.

Almost surely, 2^102505840 is an apocalyptic number.

102505840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102505840 is an abundant number, since it is smaller than the sum of its proper divisors (143514128).

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

102505840 is a wasteful number, since it uses less digits than its factorization.

102505840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41377 (or 41371 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 102505840 is about 10124.5167785924. The cubic root of 102505840 is about 468.0039690900.

The spelling of 102505840 in words is "one hundred two million, five hundred five thousand, eight hundred forty".