20961552 has 40 divisors (see below), whose sum is σ = 55046080. Its totient is φ = 6871680.

The previous prime is 20961529. The next prime is 20961557. The reversal of 20961552 is 25516902.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20961557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 652 + ... + 6507.

It is an arithmetic number, because the mean of its divisors is an integer number (1376152).

Almost surely, 2^20961552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20961552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27523040).

20961552 is an abundant number, since it is smaller than the sum of its proper divisors (34084528).

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

20961552 is a wasteful number, since it uses less digits than its factorization.

20961552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7231 (or 7225 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 20961552 is about 4578.3787523533. The cubic root of 20961552 is about 275.7239415765.

The spelling of 20961552 in words is "twenty million, nine hundred sixty-one thousand, five hundred fifty-two".