19972390 has 16 divisors (see below), whose sum is σ = 36173808. Its totient is φ = 7939296.

The previous prime is 19972369. The next prime is 19972423. The reversal of 19972390 is 9327991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4497 + ... + 7756.

It is an arithmetic number, because the mean of its divisors is an integer number (2260863).

Almost surely, 2^19972390 is an apocalyptic number.

19972390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19972390 is a deficient number, since it is larger than the sum of its proper divisors (16201418).

19972390 is a wasteful number, since it uses less digits than its factorization.

19972390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12423.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 19972390 is about 4469.0479970571. The cubic root of 19972390 is about 271.3167956860.

The spelling of 19972390 in words is "nineteen million, nine hundred seventy-two thousand, three hundred ninety".