97878409 has 4 divisors (see below), whose sum is σ = 102134016. Its totient is φ = 93622804.

The previous prime is 97878371. The next prime is 97878413. The reversal of 97878409 is 90487879.

It is a happy number.

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: 90487879 = 8017 ⋅11287.

It is a cyclic number.

It is not a de Polignac number, because 97878409 - 2⁷ = 97878281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97878419) 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, 2127769 + ... + 2127814.

It is an arithmetic number, because the mean of its divisors is an integer number (25533504).

Almost surely, 2^97878409 is an apocalyptic number.

It is an amenable number.

97878409 is a deficient number, since it is larger than the sum of its proper divisors (4255607).

97878409 is a wasteful number, since it uses less digits than its factorization.

97878409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4255606.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The square root of 97878409 is about 9893.3517576199. The cubic root of 97878409 is about 460.8528742521.

The spelling of 97878409 in words is "ninety-seven million, eight hundred seventy-eight thousand, four hundred nine".