20723881 has 4 divisors (see below), whose sum is σ = 20783952. Its totient is φ = 20663812.

The previous prime is 20723869. The next prime is 20723891. The reversal of 20723881 is 18832702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20723881 - 2⁵ = 20723849 is a prime.

It is a super-2 number, since 2×20723881² = 858958487404322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20723821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29515 + ... + 30208.

It is an arithmetic number, because the mean of its divisors is an integer number (5195988).

Almost surely, 2^20723881 is an apocalyptic number.

It is an amenable number.

20723881 is a deficient number, since it is larger than the sum of its proper divisors (60071).

20723881 is an equidigital number, since it uses as much as digits as its factorization.

20723881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60070.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 20723881 is about 4552.3489541115. The cubic root of 20723881 is about 274.6778862089.

The spelling of 20723881 in words is "twenty million, seven hundred twenty-three thousand, eight hundred eighty-one".