31660631655551 has 4 divisors (see below), whose sum is σ = 31660888291992. Its totient is φ = 31660375019112.

The previous prime is 31660631655529. The next prime is 31660631655559. The reversal of 31660631655551 is 15555613606613.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31660631655551 - 2¹⁰ = 31660631654527 is a prime.

It is a super-2 number, since 2×31660631655551² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31660631655493 and 31660631655502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31660631655559) 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, 128133080 + ... + 128379933.

It is an arithmetic number, because the mean of its divisors is an integer number (7915222072998).

Almost surely, 2^{31660631655551} is an apocalyptic number.

31660631655551 is a deficient number, since it is larger than the sum of its proper divisors (256636441).

31660631655551 is a wasteful number, since it uses less digits than its factorization.

31660631655551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256636440.

The product of its (nonzero) digits is 7290000, while the sum is 53.

The spelling of 31660631655551 in words is "thirty-one trillion, six hundred sixty billion, six hundred thirty-one million, six hundred fifty-five thousand, five hundred fifty-one".