1921900 has 18 divisors (see below), whose sum is σ = 4170740. Its totient is φ = 768720.

The previous prime is 1921889. The next prime is 1921919. The reversal of 1921900 is 91291.

It is a super-2 number, since 2×1921900² = 7387399220000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9510 + ... + 9709.

2^1921900 is an apocalyptic number.

1921900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1921900 is an abundant number, since it is smaller than the sum of its proper divisors (2248840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1921900 is a wasteful number, since it uses less digits than its factorization.

1921900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19233 (or 19226 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1921900 is about 1386.3260799682. The cubic root of 1921900 is about 124.3302849285.

Subtracting from 1921900 its reverse (91291), we obtain a square (1830609 = 1353²).

The spelling of 1921900 in words is "one million, nine hundred twenty-one thousand, nine hundred".