21612077847 has 6 divisors (see below), whose sum is σ = 31217445792. Its totient is φ = 14408051892.

The previous prime is 21612077803. The next prime is 21612077983. The reversal of 21612077847 is 74877021612.

21612077847 is a `hidden beast` number, since 21 + 612 + 0 + 7 + 7 + 8 + 4 + 7 = 666.

It is not a de Polignac number, because 21612077847 - 2¹⁰ = 21612076823 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612477847) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1200670983 + ... + 1200671000.

It is an arithmetic number, because the mean of its divisors is an integer number (5202907632).

Almost surely, 2^21612077847 is an apocalyptic number.

21612077847 is a deficient number, since it is larger than the sum of its proper divisors (9605367945).

21612077847 is a wasteful number, since it uses less digits than its factorization.

21612077847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2401341989 (or 2401341986 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The spelling of 21612077847 in words is "twenty-one billion, six hundred twelve million, seventy-seven thousand, eight hundred forty-seven".