20746381 has 8 divisors (see below), whose sum is σ = 21601784. Its totient is φ = 19906560.

The previous prime is 20746379. The next prime is 20746387. The reversal of 20746381 is 18364702.

It can be written as a sum of positive squares in 4 ways, for example, as 9796900 + 10949481 = 3130^2 + 3309^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 7-Lehmer number, since φ(20746381) divides (20746381-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 20746381 - 2¹ = 20746379 is a prime.

It is a super-2 number, since 2×20746381² = 860824649194322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20746387) 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 7 ways as a sum of consecutive naturals, for example, 1140 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (2700223).

Almost surely, 2^20746381 is an apocalyptic number.

It is an amenable number.

20746381 is a deficient number, since it is larger than the sum of its proper divisors (855403).

20746381 is an equidigital number, since it uses as much as digits as its factorization.

20746381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7791.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 20746381 is about 4554.8195353933. The cubic root of 20746381 is about 274.7772565464. Note that the first 3 decimals are identical.

The spelling of 20746381 in words is "twenty million, seven hundred forty-six thousand, three hundred eighty-one".