99997977 has 4 divisors (see below), whose sum is σ = 133330640. Its totient is φ = 66665316.

The previous prime is 99997973. The next prime is 99997981. The reversal of 99997977 is 77979999.

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: 77979999 = 3 ⋅25993333.

It is an interprime number because it is at equal distance from previous prime (99997973) and next prime (99997981).

It is not a de Polignac number, because 99997977 - 2² = 99997973 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99997973) 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, 16666327 + ... + 16666332.

It is an arithmetic number, because the mean of its divisors is an integer number (33332660).

Almost surely, 2^99997977 is an apocalyptic number.

It is an amenable number.

99997977 is a deficient number, since it is larger than the sum of its proper divisors (33332663).

99997977 is a wasteful number, since it uses less digits than its factorization.

99997977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33332662.

The product of its digits is 20253807, while the sum is 66.

The square root of 99997977 is about 9999.8988494884. The cubic root of 99997977 is about 464.1557533621.

The spelling of 99997977 in words is "ninety-nine million, nine hundred ninety-seven thousand, nine hundred seventy-seven".