20734981 has 2 divisors, whose sum is σ = 20734982. Its totient is φ = 20734980.

The previous prime is 20734969. The next prime is 20734991. The reversal of 20734981 is 18943702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14130081 + 6604900 = 3759^2 + 2570^2 .

It is a cyclic number.

It is not a de Polignac number, because 20734981 - 2⁵ = 20734949 is a prime.

It is a super-2 number, since 2×20734981² = 859878874140722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20734921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10367490 + 10367491.

It is an arithmetic number, because the mean of its divisors is an integer number (10367491).

Almost surely, 2^20734981 is an apocalyptic number.

It is an amenable number.

20734981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20734981 is an equidigital number, since it uses as much as digits as its factorization.

20734981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20734981 is about 4553.5679417354. The cubic root of 20734981 is about 274.7269178929.

The spelling of 20734981 in words is "twenty million, seven hundred thirty-four thousand, nine hundred eighty-one".