645921467 has 4 divisors (see below), whose sum is σ = 647000400. Its totient is φ = 644842536.

The previous prime is 645921461. The next prime is 645921499. The reversal of 645921467 is 764129546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645921467 - 2¹⁴ = 645905083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645921461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538568 + ... + 539765.

It is an arithmetic number, because the mean of its divisors is an integer number (161750100).

Almost surely, 2^645921467 is an apocalyptic number.

645921467 is a deficient number, since it is larger than the sum of its proper divisors (1078933).

645921467 is a wasteful number, since it uses less digits than its factorization.

645921467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078932.

The product of its digits is 362880, while the sum is 44.

The square root of 645921467 is about 25414.9850875423. The cubic root of 645921467 is about 864.4235155575.

The spelling of 645921467 in words is "six hundred forty-five million, nine hundred twenty-one thousand, four hundred sixty-seven".