1997021919 has 8 divisors (see below), whose sum is σ = 2662923312. Its totient is φ = 1331234240.

The previous prime is 1997021903. The next prime is 1997021933. The reversal of 1997021919 is 9191207991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1997021919 - 2⁴ = 1997021903 is a prime.

It is a super-2 number, since 2×1997021919² = 7976193089932885122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997021219) 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, 29299 + ... + 69659.

It is an arithmetic number, because the mean of its divisors is an integer number (332865414).

Almost surely, 2^1997021919 is an apocalyptic number.

1997021919 is a deficient number, since it is larger than the sum of its proper divisors (665901393).

1997021919 is a wasteful number, since it uses less digits than its factorization.

1997021919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56857.

The product of its (nonzero) digits is 91854, while the sum is 48.

The square root of 1997021919 is about 44688.0511882091. The cubic root of 1997021919 is about 1259.2953814201.

The spelling of 1997021919 in words is "one billion, nine hundred ninety-seven million, twenty-one thousand, nine hundred nineteen".