20720699 has 4 divisors (see below), whose sum is σ = 20835360. Its totient is φ = 20606040.

The previous prime is 20720681. The next prime is 20720717. The reversal of 20720699 is 99602702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99602702 = 2 ⋅49801351.

It is an interprime number because it is at equal distance from previous prime (20720681) and next prime (20720717).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20720699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20720299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57059 + ... + 57420.

It is an arithmetic number, because the mean of its divisors is an integer number (5208840).

Almost surely, 2^20720699 is an apocalyptic number.

20720699 is a deficient number, since it is larger than the sum of its proper divisors (114661).

20720699 is a wasteful number, since it uses less digits than its factorization.

20720699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114660.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20720699 is about 4551.9994507908. Note that the first 3 decimals coincide. The cubic root of 20720699 is about 274.6638272308.

The spelling of 20720699 in words is "twenty million, seven hundred twenty thousand, six hundred ninety-nine".