66978453 has 16 divisors (see below), whose sum is σ = 95501376. Its totient is φ = 41606400.

The previous prime is 66978451. The next prime is 66978481. The reversal of 66978453 is 35487966.

It is not a de Polignac number, because 66978453 - 2¹ = 66978451 is a prime.

It is a super-2 number, since 2×66978453² = 8972226332546418, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66978451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1351 + ... + 11652.

It is an arithmetic number, because the mean of its divisors is an integer number (5968836).

Almost surely, 2^66978453 is an apocalyptic number.

It is an amenable number.

66978453 is a deficient number, since it is larger than the sum of its proper divisors (28522923).

66978453 is a wasteful number, since it uses less digits than its factorization.

66978453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13124.

The product of its digits is 1088640, while the sum is 48.

The square root of 66978453 is about 8184.0364735258. The cubic root of 66978453 is about 406.1112659849. Note that the first 3 decimals are identical.

The spelling of 66978453 in words is "sixty-six million, nine hundred seventy-eight thousand, four hundred fifty-three".