2121399431 has 2 divisors, whose sum is σ = 2121399432. Its totient is φ = 2121399430.

The previous prime is 2121399391. The next prime is 2121399463. The reversal of 2121399431 is 1349931212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2121399431 - 2¹⁰ = 2121398407 is a prime.

It is a super-2 number, since 2×2121399431² = 9000671091694247522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2121399391 and 2121399400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121399481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060699715 + 1060699716.

It is an arithmetic number, because the mean of its divisors is an integer number (1060699716).

Almost surely, 2^2121399431 is an apocalyptic number.

2121399431 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121399431 is an equidigital number, since it uses as much as digits as its factorization.

2121399431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 35.

The square root of 2121399431 is about 46058.6520753702. The cubic root of 2121399431 is about 1284.9142611621.

The spelling of 2121399431 in words is "two billion, one hundred twenty-one million, three hundred ninety-nine thousand, four hundred thirty-one".