102121440 has 96 divisors (see below), whose sum is σ = 332107776. Its totient is φ = 26350080.

The previous prime is 102121421. The next prime is 102121463. The reversal of 102121440 is 44121201.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11449 + ... + 18311.

It is an arithmetic number, because the mean of its divisors is an integer number (3459456).

Almost surely, 2^102121440 is an apocalyptic number.

102121440 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 102121440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166053888).

102121440 is an abundant number, since it is smaller than the sum of its proper divisors (229986336).

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

102121440 is a wasteful number, since it uses less digits than its factorization.

102121440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6912 (or 6904 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 102121440 is about 10105.5153258011. The cubic root of 102121440 is about 467.4182266155.

Adding to 102121440 its reverse (44121201), we get a palindrome (146242641).

The spelling of 102121440 in words is "one hundred two million, one hundred twenty-one thousand, four hundred forty".