645542701 has 4 divisors (see below), whose sum is σ = 647000352. Its totient is φ = 644085052.

The previous prime is 645542699. The next prime is 645542707. The reversal of 645542701 is 107245546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645542701 - 2¹ = 645542699 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 (645542707) 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, 728161 + ... + 729046.

It is an arithmetic number, because the mean of its divisors is an integer number (161750088).

Almost surely, 2^645542701 is an apocalyptic number.

It is an amenable number.

645542701 is a deficient number, since it is larger than the sum of its proper divisors (1457651).

645542701 is a wasteful number, since it uses less digits than its factorization.

645542701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1457650.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 645542701 is about 25407.5323673906. The cubic root of 645542701 is about 864.2545175843.

The spelling of 645542701 in words is "six hundred forty-five million, five hundred forty-two thousand, seven hundred one".