20402227961 has 2 divisors, whose sum is σ = 20402227962. Its totient is φ = 20402227960.

The previous prime is 20402227913. The next prime is 20402227991. The reversal of 20402227961 is 16972220402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20066422336 + 335805625 = 141656^2 + 18325^2 .

It is a cyclic number.

It is not a de Polignac number, because 20402227961 - 2⁶ = 20402227897 is a prime.

It is a super-2 number, since 2×20402227961² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20402227991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201113980 + 10201113981.

It is an arithmetic number, because the mean of its divisors is an integer number (10201113981).

Almost surely, 2^20402227961 is an apocalyptic number.

It is an amenable number.

20402227961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20402227961 is an equidigital number, since it uses as much as digits as its factorization.

20402227961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 35.

The spelling of 20402227961 in words is "twenty billion, four hundred two million, two hundred twenty-seven thousand, nine hundred sixty-one".