102721320 has 192 divisors, whose sum is σ = 367960320. Its totient is φ = 24694272.

The previous prime is 102721319. The next prime is 102721331. The reversal of 102721320 is 23127201.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 102721293 and 102721302.

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, 219727 + ... + 220193.

It is an arithmetic number, because the mean of its divisors is an integer number (1916460).

Almost surely, 2^102721320 is an apocalyptic number.

102721320 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 102721320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183980160).

102721320 is an abundant number, since it is smaller than the sum of its proper divisors (265239000).

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

102721320 is a wasteful number, since it uses less digits than its factorization.

102721320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 537 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 102721320 is about 10135.1526875524. The cubic root of 102721320 is about 468.3316737177.

Adding to 102721320 its reverse (23127201), we get a palindrome (125848521).

It can be divided in two parts, 102721 and 320, that added together give a square (103041 = 321²).

The spelling of 102721320 in words is "one hundred two million, seven hundred twenty-one thousand, three hundred twenty".