20720250749 has 16 divisors (see below), whose sum is σ = 23440260480. Its totient is φ = 18149520960.

The previous prime is 20720250703. The next prime is 20720250751. The reversal of 20720250749 is 94705202702.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20720250749 is a prime.

It is a super-2 number, since 2×20720250749² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20720250779) 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, 205214 + ... + 289055.

It is an arithmetic number, because the mean of its divisors is an integer number (1465016280).

Almost surely, 2^20720250749 is an apocalyptic number.

It is an amenable number.

20720250749 is a deficient number, since it is larger than the sum of its proper divisors (2720009731).

20720250749 is a wasteful number, since it uses less digits than its factorization.

20720250749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494420.

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 20720250749 in words is "twenty billion, seven hundred twenty million, two hundred fifty thousand, seven hundred forty-nine".