20778119951 has 4 divisors (see below), whose sum is σ = 20785942752. Its totient is φ = 20770297152.

The previous prime is 20778119939. The next prime is 20778119963. The reversal of 20778119951 is 15991187702.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20778119939) and next prime (20778119963).

It is a cyclic number.

It is not a de Polignac number, because 20778119951 - 2¹⁰ = 20778118927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20778119951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778116951) 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, 3907415 + ... + 3912728.

It is an arithmetic number, because the mean of its divisors is an integer number (5196485688).

Almost surely, 2^20778119951 is an apocalyptic number.

20778119951 is a deficient number, since it is larger than the sum of its proper divisors (7822801).

20778119951 is an equidigital number, since it uses as much as digits as its factorization.

20778119951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7822800.

The product of its (nonzero) digits is 317520, while the sum is 50.

The spelling of 20778119951 in words is "twenty billion, seven hundred seventy-eight million, one hundred nineteen thousand, nine hundred fifty-one".