20739381 has 16 divisors (see below), whose sum is σ = 30227904. Its totient is φ = 12570624.

The previous prime is 20739347. The next prime is 20739421. The reversal of 20739381 is 18393702.

It is not a de Polignac number, because 20739381 - 2⁷ = 20739253 is a prime.

It is a super-2 number, since 2×20739381² = 860243848526322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1356 + ... + 6581.

It is an arithmetic number, because the mean of its divisors is an integer number (1889244).

Almost surely, 2^20739381 is an apocalyptic number.

It is an amenable number.

20739381 is a deficient number, since it is larger than the sum of its proper divisors (9488523).

20739381 is a wasteful number, since it uses less digits than its factorization.

20739381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8020.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 20739381 is about 4554.0510537323. The cubic root of 20739381 is about 274.7463490327.

The spelling of 20739381 in words is "twenty million, seven hundred thirty-nine thousand, three hundred eighty-one".