53991407 has 4 divisors (see below), whose sum is σ = 56833080. Its totient is φ = 51149736.

The previous prime is 53991401. The next prime is 53991433. The reversal of 53991407 is 70419935.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70419935 = 5 ⋅14083987.

It is a cyclic number.

It is not a de Polignac number, because 53991407 - 2⁸ = 53991151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53991401) 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, 1420808 + ... + 1420845.

It is an arithmetic number, because the mean of its divisors is an integer number (14208270).

Almost surely, 2^53991407 is an apocalyptic number.

53991407 is a deficient number, since it is larger than the sum of its proper divisors (2841673).

53991407 is a wasteful number, since it uses less digits than its factorization.

53991407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2841672.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 53991407 is about 7347.8845254944. The cubic root of 53991407 is about 377.9562648279.

The spelling of 53991407 in words is "fifty-three million, nine hundred ninety-one thousand, four hundred seven".