20725761 has 8 divisors (see below), whose sum is σ = 31582144. Its totient is φ = 11843280.

The previous prime is 20725753. The next prime is 20725769. The reversal of 20725761 is 16752702.

It is an interprime number because it is at equal distance from previous prime (20725753) and next prime (20725769).

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

It is not a de Polignac number, because 20725761 - 2³ = 20725753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20725769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 493450 + ... + 493491.

It is an arithmetic number, because the mean of its divisors is an integer number (3947768).

It is a Proth number, since it is equal to 1265 ⋅ 2¹⁴ + 1 and 1265 < 2¹⁴.

Almost surely, 2^20725761 is an apocalyptic number.

20725761 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20725761 is a deficient number, since it is larger than the sum of its proper divisors (10856383).

20725761 is an equidigital number, since it uses as much as digits as its factorization.

20725761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986951.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 20725761 is about 4552.5554362358. Note that the first 3 decimals coincide. The cubic root of 20725761 is about 274.6861919057.

The spelling of 20725761 in words is "twenty million, seven hundred twenty-five thousand, seven hundred sixty-one".