21171402 has 32 divisors (see below), whose sum is σ = 53769600. Its totient is φ = 6048864.

The previous prime is 21171401. The next prime is 21171407. The reversal of 21171402 is 20417112.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21171401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27627 + ... + 28382.

It is an arithmetic number, because the mean of its divisors is an integer number (1680300).

Almost surely, 2^21171402 is an apocalyptic number.

21171402 is an abundant number, since it is smaller than the sum of its proper divisors (32598198).

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

21171402 is a wasteful number, since it uses less digits than its factorization.

21171402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56027 (or 56021 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 21171402 is about 4601.2391809164. The cubic root of 21171402 is about 276.6409959892.

Adding to 21171402 its reverse (20417112), we get a palindrome (41588514).

The spelling of 21171402 in words is "twenty-one million, one hundred seventy-one thousand, four hundred two".