20072551 has 4 divisors (see below), whose sum is σ = 20141352. Its totient is φ = 20003752.

The previous prime is 20072543. The next prime is 20072561. The reversal of 20072551 is 15527002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15527002 = 2 ⋅7763501.

It is a cyclic number.

It is not a de Polignac number, because 20072551 - 2³ = 20072543 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 (20072561) 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 3 ways as a sum of consecutive naturals, for example, 33961 + ... + 34546.

It is an arithmetic number, because the mean of its divisors is an integer number (5035338).

Almost surely, 2^20072551 is an apocalyptic number.

20072551 is a deficient number, since it is larger than the sum of its proper divisors (68801).

20072551 is an equidigital number, since it uses as much as digits as its factorization.

20072551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68800.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 20072551 is about 4480.2400605325. The cubic root of 20072551 is about 271.7695884300.

Adding to 20072551 its reverse (15527002), we get a palindrome (35599553).

The spelling of 20072551 in words is "twenty million, seventy-two thousand, five hundred fifty-one".