2135616421 has 2 divisors, whose sum is σ = 2135616422. Its totient is φ = 2135616420.

The previous prime is 2135616419. The next prime is 2135616437. The reversal of 2135616421 is 1246165312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1524043521 + 611572900 = 39039^2 + 24730^2 .

It is a cyclic number.

It is not a de Polignac number, because 2135616421 - 2¹ = 2135616419 is a prime.

Together with 2135616419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2135716421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1067808210 + 1067808211.

It is an arithmetic number, because the mean of its divisors is an integer number (1067808211).

Almost surely, 2^2135616421 is an apocalyptic number.

It is an amenable number.

2135616421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2135616421 is an equidigital number, since it uses as much as digits as its factorization.

2135616421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 31.

The square root of 2135616421 is about 46212.7300751644. The cubic root of 2135616421 is about 1287.7782442719.

The spelling of 2135616421 in words is "two billion, one hundred thirty-five million, six hundred sixteen thousand, four hundred twenty-one".