1897478949 has 4 divisors (see below), whose sum is σ = 2529971936. Its totient is φ = 1264985964.

The previous prime is 1897478941. The next prime is 1897478951. The reversal of 1897478949 is 9498747981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1897478949 - 2³ = 1897478941 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1897478949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1897478941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316246489 + ... + 316246494.

It is an arithmetic number, because the mean of its divisors is an integer number (632492984).

Almost surely, 2^1897478949 is an apocalyptic number.

It is an amenable number.

1897478949 is a deficient number, since it is larger than the sum of its proper divisors (632492987).

1897478949 is an equidigital number, since it uses as much as digits as its factorization.

1897478949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632492986.

The product of its digits is 36578304, while the sum is 66.

The square root of 1897478949 is about 43560.0613980284. The cubic root of 1897478949 is about 1238.0142838655.

The spelling of 1897478949 in words is "one billion, eight hundred ninety-seven million, four hundred seventy-eight thousand, nine hundred forty-nine".