661156433 has 32 divisors (see below), whose sum is σ = 819456000. Its totient is φ = 520805376.

The previous prime is 661156427. The next prime is 661156481. The reversal of 661156433 is 334651166.

It is not a de Polignac number, because 661156433 - 2²⁰ = 660107857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661156393 and 661156402.

It is not an unprimeable number, because it can be changed into a prime (661156423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1103468 + ... + 1104066.

It is an arithmetic number, because the mean of its divisors is an integer number (25608000).

Almost surely, 2^661156433 is an apocalyptic number.

It is an amenable number.

661156433 is a deficient number, since it is larger than the sum of its proper divisors (158299567).

661156433 is a wasteful number, since it uses less digits than its factorization.

661156433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861.

The product of its digits is 38880, while the sum is 35.

The square root of 661156433 is about 25712.9623536457. The cubic root of 661156433 is about 871.1669868150.

The spelling of 661156433 in words is "six hundred sixty-one million, one hundred fifty-six thousand, four hundred thirty-three".