19979893 has 4 divisors (see below), whose sum is σ = 20848608. Its totient is φ = 19111180.

The previous prime is 19979891. The next prime is 19979899. The reversal of 19979893 is 39897991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39897991 = 7 ⋅5699713.

It is a cyclic number.

It is not a de Polignac number, because 19979893 - 2¹ = 19979891 is a prime.

It is a super-2 number, since 2×19979893² = 798392248582898, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19979891) 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, 434323 + ... + 434368.

It is an arithmetic number, because the mean of its divisors is an integer number (5212152).

Almost surely, 2^19979893 is an apocalyptic number.

It is an amenable number.

19979893 is a deficient number, since it is larger than the sum of its proper divisors (868715).

19979893 is an equidigital number, since it uses as much as digits as its factorization.

19979893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868714.

The product of its digits is 1102248, while the sum is 55.

The square root of 19979893 is about 4469.8873587597. The cubic root of 19979893 is about 271.3507665003.

The spelling of 19979893 in words is "nineteen million, nine hundred seventy-nine thousand, eight hundred ninety-three".