645210061 has 8 divisors (see below), whose sum is σ = 688080960. Its totient is φ = 602885568.

The previous prime is 645210023. The next prime is 645210089. The reversal of 645210061 is 160012546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645210061 - 2¹⁵ = 645177293 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 (645210091) 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, 134161 + ... + 138886.

It is an arithmetic number, because the mean of its divisors is an integer number (86010120).

Almost surely, 2^645210061 is an apocalyptic number.

It is an amenable number.

645210061 is a deficient number, since it is larger than the sum of its proper divisors (42870899).

645210061 is a wasteful number, since it uses less digits than its factorization.

645210061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273203.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 645210061 is about 25400.9854336402. The cubic root of 645210061 is about 864.1060456006.

It can be divided in two parts, 64 and 5210061, that added together give a palindrome (5210125).

The spelling of 645210061 in words is "six hundred forty-five million, two hundred ten thousand, sixty-one".