1408135621 has 2 divisors, whose sum is σ = 1408135622. Its totient is φ = 1408135620.

The previous prime is 1408135613. The next prime is 1408135649. The reversal of 1408135621 is 1265318041.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 870545025 + 537590596 = 29505^2 + 23186^2 .

It is a cyclic number.

It is not a de Polignac number, because 1408135621 - 2³ = 1408135613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1408135691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 704067810 + 704067811.

It is an arithmetic number, because the mean of its divisors is an integer number (704067811).

Almost surely, 2^1408135621 is an apocalyptic number.

It is an amenable number.

1408135621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1408135621 is an equidigital number, since it uses as much as digits as its factorization.

1408135621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 1408135621 is about 37525.1331909695. The cubic root of 1408135621 is about 1120.8517174113.

The spelling of 1408135621 in words is "one billion, four hundred eight million, one hundred thirty-five thousand, six hundred twenty-one".