645121302126 has 32 divisors (see below), whose sum is σ = 1480044648960. Its totient is φ = 183635162976.

The previous prime is 645121302121. The next prime is 645121302143. The reversal of 645121302126 is 621203121546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645121302121) 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, 28538946 + ... + 28561541.

It is an arithmetic number, because the mean of its divisors is an integer number (46251395280).

Almost surely, 2^645121302126 is an apocalyptic number.

645121302126 is an abundant number, since it is smaller than the sum of its proper divisors (834923346834).

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

645121302126 is a wasteful number, since it uses less digits than its factorization.

645121302126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57100768.

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 645121302126 in words is "six hundred forty-five billion, one hundred twenty-one million, three hundred two thousand, one hundred twenty-six".