646021263501461 has 4 divisors (see below), whose sum is σ = 647479550778432. Its totient is φ = 644562976224492.

The previous prime is 646021263501347. The next prime is 646021263501473. The reversal of 646021263501461 is 164105362120646.

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 a de Polignac number, because none of the positive numbers 2^k-646021263501461 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 (646021263501491) 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, 729143637821 + ... + 729143638706.

It is an arithmetic number, because the mean of its divisors is an integer number (161869887694608).

Almost surely, 2^{646021263501461} is an apocalyptic number.

It is an amenable number.

646021263501461 is a deficient number, since it is larger than the sum of its proper divisors (1458287276971).

646021263501461 is a wasteful number, since it uses less digits than its factorization.

646021263501461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458287276970.

The product of its (nonzero) digits is 1244160, while the sum is 47.

The spelling of 646021263501461 in words is "six hundred forty-six trillion, twenty-one billion, two hundred sixty-three million, five hundred one thousand, four hundred sixty-one".