66416251661466 has 128 divisors (see below), whose sum is σ = 158613570994176. Its totient is φ = 18148697333760.

The previous prime is 66416251661429. The next prime is 66416251661587. The reversal of 66416251661466 is 66416615261466.

It is a super-2 number, since 2×66416251661466² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13740586 + ... + 17934218.

It is an arithmetic number, because the mean of its divisors is an integer number (1239168523392).

Almost surely, 2^{66416251661466} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66416251661466, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79306785497088).

66416251661466 is an abundant number, since it is smaller than the sum of its proper divisors (92197319332710).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66416251661466 is a wasteful number, since it uses less digits than its factorization.

66416251661466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4193876.

The product of its digits is 44789760, while the sum is 60.

The spelling of 66416251661466 in words is "sixty-six trillion, four hundred sixteen billion, two hundred fifty-one million, six hundred sixty-one thousand, four hundred sixty-six".