66607905 has 48 divisors (see below), whose sum is σ = 133527744. Its totient is φ = 28103040.

The previous prime is 66607889. The next prime is 66607907. The reversal of 66607905 is 50970666.

It is a happy number.

It is not a de Polignac number, because 66607905 - 2⁴ = 66607889 is a prime.

It is a super-2 number, since 2×66607905² = 8873226016978050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (66607907) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6070 + ... + 13040.

It is an arithmetic number, because the mean of its divisors is an integer number (2781828).

Almost surely, 2^66607905 is an apocalyptic number.

66607905 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66607905 is an abundant number, since it is smaller than the sum of its proper divisors (66919839).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66607905 is a wasteful number, since it uses less digits than its factorization.

66607905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7006 (or 6999 counting only the distinct ones).

The product of its (nonzero) digits is 68040, while the sum is 39.

The square root of 66607905 is about 8161.3666135029. The cubic root of 66607905 is about 405.3609645766.

The spelling of 66607905 in words is "sixty-six million, six hundred seven thousand, nine hundred five".