21056176867401 has 27 divisors (see below), whose sum is σ = 32934300141639. Its totient is φ = 12957537174192.

The previous prime is 21056176867373. The next prime is 21056176867423. The reversal of 21056176867401 is 10476867165012.

The square root of 21056176867401 is 4588701.

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

21056176867401 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 6 + 176 + 8 + 67 + 401 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3114819063225 + 17941357804176 = 1764885^2 + 4235724^2 .

It is not a de Polignac number, because 21056176867401 - 2³¹ = 21054029383753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21056176867601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 178900510 + ... + 179018168.

Almost surely, 2^{21056176867401} is an apocalyptic number.

21056176867401 is the 4588701-st square number.

21056176867401 is the 2294351-st centered octagonal number.

It is an amenable number.

21056176867401 is a deficient number, since it is larger than the sum of its proper divisors (11878123274238).

21056176867401 is an frugal number, since it uses more digits than its factorization.

21056176867401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235350 (or 117675 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 21056176867401 in words is "twenty-one trillion, fifty-six billion, one hundred seventy-six million, eight hundred sixty-seven thousand, four hundred one".