645079898 has 16 divisors (see below), whose sum is σ = 972886464. Its totient is φ = 320789280.

The previous prime is 645079891. The next prime is 645079969. The reversal of 645079898 is 898970546.

645079898 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×645079898² = 832256149607380808, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (645079891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 542861 + ... + 544047.

It is an arithmetic number, because the mean of its divisors is an integer number (60805404).

Almost surely, 2^645079898 is an apocalyptic number.

645079898 is a deficient number, since it is larger than the sum of its proper divisors (327806566).

645079898 is a wasteful number, since it uses less digits than its factorization.

645079898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2437.

The product of its (nonzero) digits is 4354560, while the sum is 56.

The square root of 645079898 is about 25398.4231400298. The cubic root of 645079898 is about 864.0479341904.

The spelling of 645079898 in words is "six hundred forty-five million, seventy-nine thousand, eight hundred ninety-eight".