53978309 has 32 divisors (see below), whose sum is σ = 72714240. Its totient is φ = 38808000.

The previous prime is 53978299. The next prime is 53978311. The reversal of 53978309 is 90387935.

53978309 = T₂₁₅₅ + T₂₁₅₆ + ... + T₂₁₇₇.

It is not a de Polignac number, because 53978309 - 2⁴ = 53978293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 53978309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53978369) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50834 + ... + 51884.

It is an arithmetic number, because the mean of its divisors is an integer number (2272320).

Almost surely, 2^53978309 is an apocalyptic number.

It is an amenable number.

53978309 is a deficient number, since it is larger than the sum of its proper divisors (18735931).

53978309 is a wasteful number, since it uses less digits than its factorization.

53978309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 53978309 is about 7346.9931944980. The cubic root of 53978309 is about 377.9256990286.

The spelling of 53978309 in words is "fifty-three million, nine hundred seventy-eight thousand, three hundred nine".