102042640 has 80 divisors (see below), whose sum is σ = 276982272. Its totient is φ = 34232832.

The previous prime is 102042631. The next prime is 102042643. The reversal of 102042640 is 46240201.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (102042643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24382 + ... + 28258.

Almost surely, 2^102042640 is an apocalyptic number.

102042640 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 102042640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138491136).

102042640 is an abundant number, since it is smaller than the sum of its proper divisors (174939632).

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

102042640 is a wasteful number, since it uses less digits than its factorization.

102042640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944 (or 3938 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 102042640 is about 10101.6157123502. The cubic root of 102042640 is about 467.2979709864.

Adding to 102042640 its reverse (46240201), we get a palindrome (148282841).

It can be divided in two parts, 1020 and 42640, that added together give a triangular number (43660 = T₂₉₅).

The spelling of 102042640 in words is "one hundred two million, forty-two thousand, six hundred forty".