661428406262 has 64 divisors (see below), whose sum is σ = 1190567669760. Its totient is φ = 272837980800.

The previous prime is 661428406187. The next prime is 661428406319. The reversal of 661428406262 is 262604824166.

It is a super-2 number, since 2×661428406262² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77564 + ... + 1152767.

It is an arithmetic number, because the mean of its divisors is an integer number (18602619840).

Almost surely, 2^661428406262 is an apocalyptic number.

661428406262 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

661428406262 is a deficient number, since it is larger than the sum of its proper divisors (529139263498).

661428406262 is a wasteful number, since it uses less digits than its factorization.

661428406262 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230429.

The product of its (nonzero) digits is 1327104, while the sum is 47.

The spelling of 661428406262 in words is "six hundred sixty-one billion, four hundred twenty-eight million, four hundred six thousand, two hundred sixty-two".