661626216436 has 12 divisors (see below), whose sum is σ = 1218785135680. Its totient is φ = 313401891960.

The previous prime is 661626216403. The next prime is 661626216443. The reversal of 661626216436 is 634612626166.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 661626216436.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4352803980 + ... + 4352804131.

Almost surely, 2^661626216436 is an apocalyptic number.

It is an amenable number.

661626216436 is a deficient number, since it is larger than the sum of its proper divisors (557158919244).

661626216436 is a wasteful number, since it uses less digits than its factorization.

661626216436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8705608134 (or 8705608132 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 49.

The spelling of 661626216436 in words is "six hundred sixty-one billion, six hundred twenty-six million, two hundred sixteen thousand, four hundred thirty-six".