21172002 has 16 divisors (see below), whose sum is σ = 43038912. Its totient is φ = 6941520.

The previous prime is 21171991. The next prime is 21172003. The reversal of 21172002 is 20027112.

It is not an unprimeable number, because it can be changed into a prime (21172003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28558 + ... + 29289.

It is an arithmetic number, because the mean of its divisors is an integer number (2689932).

Almost surely, 2^21172002 is an apocalyptic number.

21172002 is an abundant number, since it is smaller than the sum of its proper divisors (21866910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21172002 is a wasteful number, since it uses less digits than its factorization.

21172002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57913.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21172002 is about 4601.3043802817. The cubic root of 21172002 is about 276.6436093105.

Adding to 21172002 its reverse (20027112), we get a palindrome (41199114).

The spelling of 21172002 in words is "twenty-one million, one hundred seventy-two thousand, two".