102021644 has 6 divisors (see below), whose sum is σ = 178537884. Its totient is φ = 51010820.

The previous prime is 102021643. The next prime is 102021649. The reversal of 102021644 is 446120201.

It is not an unprimeable number, because it can be changed into a prime (102021643) by changing a digit.

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 as a sum of consecutive naturals, namely, 12752702 + ... + 12752709.

It is an arithmetic number, because the mean of its divisors is an integer number (29756314).

Almost surely, 2^102021644 is an apocalyptic number.

It is an amenable number.

102021644 is a deficient number, since it is larger than the sum of its proper divisors (76516240).

102021644 is a wasteful number, since it uses less digits than its factorization.

102021644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25505415 (or 25505413 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 102021644 is about 10100.5764191951. The cubic root of 102021644 is about 467.2659188260.

Adding to 102021644 its reverse (446120201), we get a palindrome (548141845).

The spelling of 102021644 in words is "one hundred two million, twenty-one thousand, six hundred forty-four".