1949401921 has 2 divisors, whose sum is σ = 1949401922. Its totient is φ = 1949401920.

The previous prime is 1949401901. The next prime is 1949401967. The reversal of 1949401921 is 1291049491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1927649025 + 21752896 = 43905^2 + 4664^2 .

It is an emirp because it is prime and its reverse (1291049491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1949401921 - 2¹¹ = 1949399873 is a prime.

It is not a weakly prime, because it can be changed into another prime (1949401901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 974700960 + 974700961.

It is an arithmetic number, because the mean of its divisors is an integer number (974700961).

Almost surely, 2^1949401921 is an apocalyptic number.

It is an amenable number.

1949401921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1949401921 is an equidigital number, since it uses as much as digits as its factorization.

1949401921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1949401921 is about 44152.0319011481. The cubic root of 1949401921 is about 1249.2052379364.

The spelling of 1949401921 in words is "one billion, nine hundred forty-nine million, four hundred one thousand, nine hundred twenty-one".