102721920 has 128 divisors (see below), whose sum is σ = 374250240. Its totient is φ = 23476224.

The previous prime is 102721919. The next prime is 102721937. The reversal of 102721920 is 29127201.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 9619 + ... + 17261.

It is an arithmetic number, because the mean of its divisors is an integer number (2923830).

Almost surely, 2^102721920 is an apocalyptic number.

102721920 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 102721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (187125120).

102721920 is an abundant number, since it is smaller than the sum of its proper divisors (271528320).

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

102721920 is an equidigital number, since it uses as much as digits as its factorization.

102721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7672 (or 7660 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 102721920 is about 10135.1822874579. The cubic root of 102721920 is about 468.3325855650.

The spelling of 102721920 in words is "one hundred two million, seven hundred twenty-one thousand, nine hundred twenty".