19947977 has 8 divisors (see below), whose sum is σ = 23138496. Its totient is φ = 16842672.

The previous prime is 19947913. The next prime is 19947979. The reversal of 19947977 is 77974991.

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

It is not a de Polignac number, because 19947977 - 2⁶ = 19947913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19947979) 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, 20798 + ... + 21735.

It is an arithmetic number, because the mean of its divisors is an integer number (2892312).

Almost surely, 2^19947977 is an apocalyptic number.

It is an amenable number.

19947977 is a deficient number, since it is larger than the sum of its proper divisors (3190519).

19947977 is an equidigital number, since it uses as much as digits as its factorization.

19947977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42607.

The product of its digits is 1000188, while the sum is 53.

The square root of 19947977 is about 4466.3158195542. The cubic root of 19947977 is about 271.2062037213.

The spelling of 19947977 in words is "nineteen million, nine hundred forty-seven thousand, nine hundred seventy-seven".