19997051 has 4 divisors (see below), whose sum is σ = 20866512. Its totient is φ = 19127592.

The previous prime is 19997041. The next prime is 19997069. The reversal of 19997051 is 15079991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19997051 - 2¹⁸ = 19734907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19997011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 434696 + ... + 434741.

It is an arithmetic number, because the mean of its divisors is an integer number (5216628).

Almost surely, 2^19997051 is an apocalyptic number.

19997051 is a deficient number, since it is larger than the sum of its proper divisors (869461).

19997051 is an equidigital number, since it uses as much as digits as its factorization.

19997051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869460.

The product of its (nonzero) digits is 25515, while the sum is 41.

The square root of 19997051 is about 4471.8062346215. The cubic root of 19997051 is about 271.4284196411.

The spelling of 19997051 in words is "nineteen million, nine hundred ninety-seven thousand, fifty-one".