1898908421 has 2 divisors, whose sum is σ = 1898908422. Its totient is φ = 1898908420.

The previous prime is 1898908409. The next prime is 1898908447. The reversal of 1898908421 is 1248098981.

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., 1819449025 + 79459396 = 42655^2 + 8914^2 .

It is a cyclic number.

It is not a de Polignac number, because 1898908421 - 2¹⁰ = 1898907397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1898908421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1898908471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 949454210 + 949454211.

It is an arithmetic number, because the mean of its divisors is an integer number (949454211).

Almost surely, 2^1898908421 is an apocalyptic number.

It is an amenable number.

1898908421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1898908421 is an equidigital number, since it uses as much as digits as its factorization.

1898908421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 50.

The square root of 1898908421 is about 43576.4663666066. The cubic root of 1898908421 is about 1238.3250932048.

The spelling of 1898908421 in words is "one billion, eight hundred ninety-eight million, nine hundred eight thousand, four hundred twenty-one".