20477881 has 2 divisors, whose sum is σ = 20477882. Its totient is φ = 20477880.

The previous prime is 20477833. The next prime is 20477893. The reversal of 20477881 is 18877402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18275625 + 2202256 = 4275^2 + 1484^2 .

It is a cyclic number.

It is not a de Polignac number, because 20477881 - 2⁷ = 20477753 is a prime.

It is a super-2 number, since 2×20477881² = 838687220500322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20477881.

It is not a weakly prime, because it can be changed into another prime (20477381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10238940 + 10238941.

It is an arithmetic number, because the mean of its divisors is an integer number (10238941).

Almost surely, 2^20477881 is an apocalyptic number.

It is an amenable number.

20477881 is a deficient number, since it is larger than the sum of its proper divisors (1).

20477881 is an equidigital number, since it uses as much as digits as its factorization.

20477881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 20477881 is about 4525.2492749019. The cubic root of 20477881 is about 273.5867151037.

The spelling of 20477881 in words is "twenty million, four hundred seventy-seven thousand, eight hundred eighty-one".