21671950 has 12 divisors (see below), whose sum is σ = 40309920. Its totient is φ = 8668760.

The previous prime is 21671941. The next prime is 21671953. The reversal of 21671950 is 5917612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21671953) 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, 216670 + ... + 216769.

It is an arithmetic number, because the mean of its divisors is an integer number (3359160).

Almost surely, 2^21671950 is an apocalyptic number.

21671950 is a deficient number, since it is larger than the sum of its proper divisors (18637970).

21671950 is a wasteful number, since it uses less digits than its factorization.

21671950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433451 (or 433446 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21671950 is about 4655.3141677013. The cubic root of 21671950 is about 278.8042116739.

The spelling of 21671950 in words is "twenty-one million, six hundred seventy-one thousand, nine hundred fifty".