20427997 has 2 divisors, whose sum is σ = 20427998. Its totient is φ = 20427996.

The previous prime is 20427989. The next prime is 20428003. The reversal of 20427997 is 79972402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15202201 + 5225796 = 3899^2 + 2286^2 .

It is a cyclic number.

It is not a de Polignac number, because 20427997 - 2³ = 20427989 is a prime.

It is a super-2 number, since 2×20427997² = 834606122864018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20427917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10213998 + 10213999.

It is an arithmetic number, because the mean of its divisors is an integer number (10213999).

Almost surely, 2^20427997 is an apocalyptic number.

It is an amenable number.

20427997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20427997 is an equidigital number, since it uses as much as digits as its factorization.

20427997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 20427997 is about 4519.7341735992. The cubic root of 20427997 is about 273.3643825856.

The spelling of 20427997 in words is "twenty million, four hundred twenty-seven thousand, nine hundred ninety-seven".