1819661925 has 12 divisors (see below), whose sum is σ = 3008507840. Its totient is φ = 970486320.

The previous prime is 1819661923. The next prime is 1819661947. The reversal of 1819661925 is 5291669181.

It is not a de Polignac number, because 1819661925 - 2¹ = 1819661923 is a prime.

It is a super-2 number, since 2×1819661925² = 6622339042589411250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1819661923) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12131005 + ... + 12131154.

Almost surely, 2^1819661925 is an apocalyptic number.

1819661925 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1819661925 is a deficient number, since it is larger than the sum of its proper divisors (1188845915).

1819661925 is a wasteful number, since it uses less digits than its factorization.

1819661925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24262172 (or 24262167 counting only the distinct ones).

The product of its digits is 233280, while the sum is 48.

The square root of 1819661925 is about 42657.4955312662. The cubic root of 1819661925 is about 1220.8535469661.

The spelling of 1819661925 in words is "one billion, eight hundred nineteen million, six hundred sixty-one thousand, nine hundred twenty-five".