102021553 has 4 divisors (see below), whose sum is σ = 102191908. Its totient is φ = 101851200.

The previous prime is 102021551. The next prime is 102021559. The reversal of 102021553 is 355120201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 97476129 + 4545424 = 9873^2 + 2132^2 .

It is a cyclic number.

It is not a de Polignac number, because 102021553 - 2¹ = 102021551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 102021553.

It is not an unprimeable number, because it can be changed into a prime (102021551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84276 + ... + 85477.

It is an arithmetic number, because the mean of its divisors is an integer number (25547977).

Almost surely, 2^102021553 is an apocalyptic number.

It is an amenable number.

102021553 is a deficient number, since it is larger than the sum of its proper divisors (170355).

102021553 is an equidigital number, since it uses as much as digits as its factorization.

102021553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170354.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 102021553 is about 10100.5719145007. The cubic root of 102021553 is about 467.2657798973.

Adding to 102021553 its reverse (355120201), we get a palindrome (457141754).

The spelling of 102021553 in words is "one hundred two million, twenty-one thousand, five hundred fifty-three".