211631610465 has 64 divisors (see below), whose sum is σ = 410525556480. Its totient is φ = 102587143680.

The previous prime is 211631610457. The next prime is 211631610469. The reversal of 211631610465 is 564016136112.

211631610465 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 31 + 610 + 4 + 6 + 5 = 666.

It is not a de Polignac number, because 211631610465 - 2³ = 211631610457 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (211631610469) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8441589 + ... + 8466621.

It is an arithmetic number, because the mean of its divisors is an integer number (6414461820).

Almost surely, 2^211631610465 is an apocalyptic number.

It is an amenable number.

211631610465 is a deficient number, since it is larger than the sum of its proper divisors (198893946015).

211631610465 is a wasteful number, since it uses less digits than its factorization.

211631610465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30751 (or 30745 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

Adding to 211631610465 its reverse (564016136112), we get a palindrome (775647746577).

The spelling of 211631610465 in words is "two hundred eleven billion, six hundred thirty-one million, six hundred ten thousand, four hundred sixty-five".