2121956801 has 2 divisors, whose sum is σ = 2121956802. Its totient is φ = 2121956800.

The previous prime is 2121956783. The next prime is 2121956807. The reversal of 2121956801 is 1086591212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2029412401 + 92544400 = 45049^2 + 9620^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121956801 - 2²⁶ = 2054847937 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2121956807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060978400 + 1060978401.

It is an arithmetic number, because the mean of its divisors is an integer number (1060978401).

Almost surely, 2^2121956801 is an apocalyptic number.

It is an amenable number.

2121956801 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121956801 is an equidigital number, since it uses as much as digits as its factorization.

2121956801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 2121956801 is about 46064.7023326972. The cubic root of 2121956801 is about 1285.0267827895.

The spelling of 2121956801 in words is "two billion, one hundred twenty-one million, nine hundred fifty-six thousand, eight hundred one".