19921404 has 48 divisors (see below), whose sum is σ = 49109760. Its totient is φ = 6272640.

The previous prime is 19921387. The next prime is 19921417. The reversal of 19921404 is 40412991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24159 + ... + 24969.

It is an arithmetic number, because the mean of its divisors is an integer number (1023120).

Almost surely, 2^19921404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19921404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24554880).

19921404 is an abundant number, since it is smaller than the sum of its proper divisors (29188356).

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

19921404 is a wasteful number, since it uses less digits than its factorization.

19921404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 930 (or 928 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 19921404 is about 4463.3400049739. The cubic root of 19921404 is about 271.0857242545.

The spelling of 19921404 in words is "nineteen million, nine hundred twenty-one thousand, four hundred four".