516215666 has 8 divisors (see below), whose sum is σ = 793209564. Its totient is φ = 251812480.

The previous prime is 516215663. The next prime is 516215677. The reversal of 516215666 is 666512615.

It can be written as a sum of positive squares in 2 ways, for example, as 506475025 + 9740641 = 22505^2 + 3121^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×516215666² = 532957227647647112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (516215663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3147575 + ... + 3147738.

Almost surely, 2^516215666 is an apocalyptic number.

516215666 is a deficient number, since it is larger than the sum of its proper divisors (276993898).

516215666 is a wasteful number, since it uses less digits than its factorization.

516215666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6295356.

The product of its digits is 64800, while the sum is 38.

The square root of 516215666 is about 22720.3799704142. The cubic root of 516215666 is about 802.1896606398.

The spelling of 516215666 in words is "five hundred sixteen million, two hundred fifteen thousand, six hundred sixty-six".