20942551 has 8 divisors (see below), whose sum is σ = 24423200. Its totient is φ = 17950464.

The previous prime is 20942527. The next prime is 20942557. The reversal of 20942551 is 15524902.

It is not a de Polignac number, because 20942551 - 2⁷ = 20942423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20942557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30186 + ... + 30871.

It is an arithmetic number, because the mean of its divisors is an integer number (3052900).

Almost surely, 2^20942551 is an apocalyptic number.

20942551 is a deficient number, since it is larger than the sum of its proper divisors (3480649).

20942551 is an frugal number, since it uses more digits than its factorization.

20942551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61078 (or 61064 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 20942551 is about 4576.3032023676. The cubic root of 20942551 is about 275.6406046427.

The spelling of 20942551 in words is "twenty million, nine hundred forty-two thousand, five hundred fifty-one".