19953990 has 96 divisors (see below), whose sum is σ = 62449920. Its totient is φ = 4318272.

The previous prime is 19953979. The next prime is 19954027. The reversal of 19953990 is 9935991.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11137 + ... + 12803.

It is an arithmetic number, because the mean of its divisors is an integer number (650520).

Almost surely, 2^19953990 is an apocalyptic number.

19953990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19953990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31224960).

19953990 is an abundant number, since it is smaller than the sum of its proper divisors (42495930).

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

19953990 is a wasteful number, since it uses less digits than its factorization.

19953990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1706 (or 1703 counting only the distinct ones).

The product of its (nonzero) digits is 98415, while the sum is 45.

The square root of 19953990 is about 4466.9889187237. The cubic root of 19953990 is about 271.2334512475.

The spelling of 19953990 in words is "nineteen million, nine hundred fifty-three thousand, nine hundred ninety".