102021520 has 20 divisors (see below), whose sum is σ = 237200220. Its totient is φ = 40808576.

The previous prime is 102021511. The next prime is 102021541. The reversal of 102021520 is 25120201.

It can be written as a sum of positive squares in 2 ways, for example, as 40806544 + 61214976 = 6388^2 + 7824^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×102021520² = 20816781086220800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 102021520.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 637555 + ... + 637714.

It is an arithmetic number, because the mean of its divisors is an integer number (11860011).

Almost surely, 2^102021520 is an apocalyptic number.

102021520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102021520 is an abundant number, since it is smaller than the sum of its proper divisors (135178700).

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

102021520 is a wasteful number, since it uses less digits than its factorization.

102021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1275282 (or 1275276 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 102021520 is about 10100.5702809297. The cubic root of 102021520 is about 467.2657295165.

Adding to 102021520 its reverse (25120201), we get a palindrome (127141721).

The spelling of 102021520 in words is "one hundred two million, twenty-one thousand, five hundred twenty".