215285792121 has 27 divisors (see below), whose sum is σ = 312875977167. Its totient is φ = 142648778160.

The previous prime is 215285792119. The next prime is 215285792131. The reversal of 215285792121 is 121297582512.

It is a happy number.

The square root of 215285792121 is 463989.

It is a perfect power (a square), and thus also a powerful number.

215285792121 is a `hidden beast` number, since 2 + 1 + 52 + 8 + 579 + 2 + 1 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 210612155625 + 4673636496 = 458925^2 + 68364^2 .

It is not a de Polignac number, because 215285792121 - 2¹ = 215285792119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215285792131) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 293704671 + ... + 293705403.

Almost surely, 2^215285792121 is an apocalyptic number.

215285792121 is the 463989-th square number.

215285792121 is the 231995-th centered octagonal number.

It is an amenable number.

215285792121 is a deficient number, since it is larger than the sum of its proper divisors (97590185046).

215285792121 is an frugal number, since it uses more digits than its factorization.

215285792121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1894 (or 947 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The spelling of 215285792121 in words is "two hundred fifteen billion, two hundred eighty-five million, seven hundred ninety-two thousand, one hundred twenty-one".