20536551 has 32 divisors (see below), whose sum is σ = 35013120. Its totient is φ = 11653632.

The previous prime is 20536547. The next prime is 20536589. The reversal of 20536551 is 15563502.

20536551 is a `hidden beast` number, since 2 + 0 + 5 + 3 + 655 + 1 = 666.

It is not a de Polignac number, because 20536551 - 2² = 20536547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20536751) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36196 + ... + 36758.

It is an arithmetic number, because the mean of its divisors is an integer number (1094160).

Almost surely, 2^20536551 is an apocalyptic number.

20536551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20536551 is a deficient number, since it is larger than the sum of its proper divisors (14476569).

20536551 is a wasteful number, since it uses less digits than its factorization.

20536551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772 (or 766 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 20536551 is about 4531.7271541875. The cubic root of 20536551 is about 273.8477451663.

The spelling of 20536551 in words is "twenty million, five hundred thirty-six thousand, five hundred fifty-one".