21102002 has 4 divisors (see below), whose sum is σ = 31653006. Its totient is φ = 10551000.

The previous prime is 21101963. The next prime is 21102023. The reversal of 21102002 is 20020112.

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

It can be written as a sum of positive squares in only one way, i.e., 19616041 + 1485961 = 4429^2 + 1219^2 .

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275499 + ... + 5275502.

Almost surely, 2^21102002 is an apocalyptic number.

21102002 is a deficient number, since it is larger than the sum of its proper divisors (10551004).

21102002 is a wasteful number, since it uses less digits than its factorization.

21102002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10551003.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21102002 is about 4593.6915438458. The cubic root of 21102002 is about 276.3383880745.

Adding to 21102002 its reverse (20020112), we get a palindrome (41122114).

The spelling of 21102002 in words is "twenty-one million, one hundred two thousand, two".