20728373 has 4 divisors (see below), whose sum is σ = 21819360. Its totient is φ = 19637388.

The previous prime is 20728339. The next prime is 20728387. The reversal of 20728373 is 37382702.

It is a happy number.

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 20728373 - 2²² = 16534069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20728273) 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, 545465 + ... + 545502.

It is an arithmetic number, because the mean of its divisors is an integer number (5454840).

Almost surely, 2^20728373 is an apocalyptic number.

It is an amenable number.

20728373 is a deficient number, since it is larger than the sum of its proper divisors (1090987).

20728373 is a wasteful number, since it uses less digits than its factorization.

20728373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090986.

The product of its (nonzero) digits is 14112, while the sum is 32.

The square root of 20728373 is about 4552.8422990479. The cubic root of 20728373 is about 274.6977306890.

The spelling of 20728373 in words is "twenty million, seven hundred twenty-eight thousand, three hundred seventy-three".