19970990 has 16 divisors (see below), whose sum is σ = 38713248. Its totient is φ = 7373856.

The previous prime is 19970987. The next prime is 19970999. The reversal of 19970990 is 9907991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19970999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76682 + ... + 76941.

It is an arithmetic number, because the mean of its divisors is an integer number (2419578).

Almost surely, 2^19970990 is an apocalyptic number.

19970990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19970990 is a deficient number, since it is larger than the sum of its proper divisors (18742258).

19970990 is a wasteful number, since it uses less digits than its factorization.

19970990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153643.

The product of its (nonzero) digits is 45927, while the sum is 44.

The square root of 19970990 is about 4468.8913614005. The cubic root of 19970990 is about 271.3104560610.

The spelling of 19970990 in words is "nineteen million, nine hundred seventy thousand, nine hundred ninety".