21371650 has 12 divisors (see below), whose sum is σ = 39751362. Its totient is φ = 8548640.

The previous prime is 21371627. The next prime is 21371653. The reversal of 21371650 is 5617312.

It can be written as a sum of positive squares in 3 ways, for example, as 20602521 + 769129 = 4539^2 + 877^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21371653) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 213667 + ... + 213766.

Almost surely, 2^21371650 is an apocalyptic number.

21371650 is a deficient number, since it is larger than the sum of its proper divisors (18379712).

21371650 is a wasteful number, since it uses less digits than its factorization.

21371650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427445 (or 427440 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21371650 is about 4622.9481935233. The cubic root of 21371650 is about 277.5104560084.

Adding to 21371650 its reverse (5617312), we get a palindrome (26988962).

The spelling of 21371650 in words is "twenty-one million, three hundred seventy-one thousand, six hundred fifty".