521226891 has 12 divisors (see below), whose sum is σ = 771246840. Its totient is φ = 339009120.

The previous prime is 521226887. The next prime is 521226907. The reversal of 521226891 is 198622125.

It is not a de Polignac number, because 521226891 - 2² = 521226887 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (521226841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 705901 + ... + 706638.

It is an arithmetic number, because the mean of its divisors is an integer number (64270570).

Almost surely, 2^521226891 is an apocalyptic number.

521226891 is a deficient number, since it is larger than the sum of its proper divisors (250019949).

521226891 is a wasteful number, since it uses less digits than its factorization.

521226891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412586 (or 1412583 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 521226891 is about 22830.3940176248. The cubic root of 521226891 is about 804.7770898820. Note that the first 3 decimals are identical.

The spelling of 521226891 in words is "five hundred twenty-one million, two hundred twenty-six thousand, eight hundred ninety-one".