21770525 has 24 divisors (see below), whose sum is σ = 31855104. Its totient is φ = 14443200.

The previous prime is 21770521. The next prime is 21770531. The reversal of 21770525 is 52507712.

It is not a de Polignac number, because 21770525 - 2² = 21770521 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3419 + ... + 7431.

It is an arithmetic number, because the mean of its divisors is an integer number (1327296).

Almost surely, 2^21770525 is an apocalyptic number.

21770525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21770525 is a deficient number, since it is larger than the sum of its proper divisors (10084579).

21770525 is a wasteful number, since it uses less digits than its factorization.

21770525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4061 (or 4056 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 21770525 is about 4665.8895186234. The cubic root of 21770525 is about 279.2262866154.

The spelling of 21770525 in words is "twenty-one million, seven hundred seventy thousand, five hundred twenty-five".