351620635666 has 4 divisors (see below), whose sum is σ = 527430953502. Its totient is φ = 175810317832.

The previous prime is 351620635661. The next prime is 351620635727. The reversal of 351620635666 is 666536026153.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666536026153 = 829 ⋅804024157.

It can be written as a sum of positive squares in only one way, i.e., 320690027025 + 30930608641 = 566295^2 + 175871^2 .

It is a super-2 number, since 2×351620635666² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (351620635661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 87905158915 + ... + 87905158918.

Almost surely, 2^351620635666 is an apocalyptic number.

351620635666 is a deficient number, since it is larger than the sum of its proper divisors (175810317836).

351620635666 is a wasteful number, since it uses less digits than its factorization.

351620635666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175810317835.

The product of its (nonzero) digits is 3499200, while the sum is 49.

The spelling of 351620635666 in words is "three hundred fifty-one billion, six hundred twenty million, six hundred thirty-five thousand, six hundred sixty-six".