102500021 has 12 divisors (see below), whose sum is σ = 117523332. Its totient is φ = 89047296.

The previous prime is 102500009. The next prime is 102500023. The reversal of 102500021 is 120005201.

It can be written as a sum of positive squares in 6 ways, for example, as 1999396 + 100500625 = 1414^2 + 10025^2 .

It is not a de Polignac number, because 102500021 - 2¹⁰ = 102498997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102499975 and 102500011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102500023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14966 + ... + 20711.

It is an arithmetic number, because the mean of its divisors is an integer number (9793611).

Almost surely, 2^102500021 is an apocalyptic number.

It is an amenable number.

102500021 is a deficient number, since it is larger than the sum of its proper divisors (15023311).

102500021 is a wasteful number, since it uses less digits than its factorization.

102500021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35720 (or 35707 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 102500021 is about 10124.2294027743. The cubic root of 102500021 is about 467.9951131177.

Adding to 102500021 its reverse (120005201), we get a palindrome (222505222).

The spelling of 102500021 in words is "one hundred two million, five hundred thousand, twenty-one".