20529881 has 2 divisors, whose sum is σ = 20529882. Its totient is φ = 20529880.

The previous prime is 20529851. The next prime is 20529911. The reversal of 20529881 is 18892502.

It is a balanced prime because it is at equal distance from previous prime (20529851) and next prime (20529911).

It can be written as a sum of positive squares in only one way, i.e., 17347225 + 3182656 = 4165^2 + 1784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20529881 is a prime.

It is a super-2 number, since 2×20529881² = 842952027748322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20529851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264940 + 10264941.

It is an arithmetic number, because the mean of its divisors is an integer number (10264941).

Almost surely, 2^20529881 is an apocalyptic number.

It is an amenable number.

20529881 is a deficient number, since it is larger than the sum of its proper divisors (1).

20529881 is an equidigital number, since it uses as much as digits as its factorization.

20529881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 20529881 is about 4530.9911719181. The cubic root of 20529881 is about 273.8180945814.

It can be divided in two parts, 205298 and 81, that added together give a cube (205379 = 59³).

The spelling of 20529881 in words is "twenty million, five hundred twenty-nine thousand, eight hundred eighty-one".