669764221542 has 192 divisors, whose sum is σ = 1615334482944. Its totient is φ = 199268467200.

The previous prime is 669764221531. The next prime is 669764221639. The reversal of 669764221542 is 245122467966.

669764221542 is a `hidden beast` number, since 6 + 6 + 9 + 76 + 4 + 2 + 21 + 542 = 666.

It is a super-2 number, since 2×669764221542² (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 (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 707247913 + ... + 707248859.

It is an arithmetic number, because the mean of its divisors is an integer number (8413200432).

Almost surely, 2^669764221542 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669764221542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (807667241472).

669764221542 is an abundant number, since it is smaller than the sum of its proper divisors (945570261402).

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

669764221542 is a wasteful number, since it uses less digits than its factorization.

669764221542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1723 (or 1720 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 54.

The spelling of 669764221542 in words is "six hundred sixty-nine billion, seven hundred sixty-four million, two hundred twenty-one thousand, five hundred forty-two".