21193550 has 48 divisors (see below), whose sum is σ = 47437440. Its totient is φ = 6881760.

The previous prime is 21193541. The next prime is 21193559. The reversal of 21193550 is 5539112.

It is an interprime number because it is at equal distance from previous prime (21193541) and next prime (21193559).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21193559) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5057 + ... + 8243.

It is an arithmetic number, because the mean of its divisors is an integer number (988280).

Almost surely, 2^21193550 is an apocalyptic number.

21193550 is an abundant number, since it is smaller than the sum of its proper divisors (26243890).

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

21193550 is a wasteful number, since it uses less digits than its factorization.

21193550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3225 (or 3220 counting only the distinct ones).

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 21193550 is about 4603.6452947637. The cubic root of 21193550 is about 276.7374296825.

The spelling of 21193550 in words is "twenty-one million, one hundred ninety-three thousand, five hundred fifty".