2121920431 has 2 divisors, whose sum is σ = 2121920432. Its totient is φ = 2121920430.

The previous prime is 2121920429. The next prime is 2121920447. The reversal of 2121920431 is 1340291212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121920431 - 2¹ = 2121920429 is a prime.

It is a super-2 number, since 2×2121920431² = 9005092630990451522, which contains 22 as substring.

Together with 2121920429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2121920396 and 2121920405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121920461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060960215 + 1060960216.

It is an arithmetic number, because the mean of its divisors is an integer number (1060960216).

Almost surely, 2^2121920431 is an apocalyptic number.

2121920431 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121920431 is an equidigital number, since it uses as much as digits as its factorization.

2121920431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 2121920431 is about 46064.3075601924. The cubic root of 2121920431 is about 1285.0194410297.

The spelling of 2121920431 in words is "two billion, one hundred twenty-one million, nine hundred twenty thousand, four hundred thirty-one".