102220021 has 4 divisors (see below), whose sum is σ = 102312652. Its totient is φ = 102127392.

The previous prime is 102220007. The next prime is 102220039. The reversal of 102220021 is 120022201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120022201 = 13 ⋅9232477.

It can be written as a sum of positive squares in 2 ways, for example, as 4901796 + 97318225 = 2214^2 + 9865^2 .

It is a cyclic number.

It is not a de Polignac number, because 102220021 - 2⁷ = 102219893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102224021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44640 + ... + 46873.

It is an arithmetic number, because the mean of its divisors is an integer number (25578163).

Almost surely, 2^102220021 is an apocalyptic number.

It is an amenable number.

102220021 is a deficient number, since it is larger than the sum of its proper divisors (92631).

102220021 is an equidigital number, since it uses as much as digits as its factorization.

102220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92630.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 102220021 is about 10110.3917332614. The cubic root of 102220021 is about 467.5685826919.

Adding to 102220021 its reverse (120022201), we get a palindrome (222242222).

The spelling of 102220021 in words is "one hundred two million, two hundred twenty thousand, twenty-one".