661902943 has 12 divisors (see below), whose sum is σ = 750793960. Its totient is φ = 578476512.

The previous prime is 661902911. The next prime is 661902977. The reversal of 661902943 is 349209166.

It is not a de Polignac number, because 661902943 - 2⁵ = 661902911 is a prime.

It is a super-2 number, since 2×661902943² = 876231011904122498, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661902896 and 661902905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661902443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 403521 + ... + 405157.

Almost surely, 2^661902943 is an apocalyptic number.

661902943 is a deficient number, since it is larger than the sum of its proper divisors (88891017).

661902943 is an equidigital number, since it uses as much as digits as its factorization.

661902943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3306 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 661902943 is about 25727.4744776863. The cubic root of 661902943 is about 871.4947409462.

The spelling of 661902943 in words is "six hundred sixty-one million, nine hundred two thousand, nine hundred forty-three".