231621487 has 2 divisors, whose sum is σ = 231621488. Its totient is φ = 231621486.

The previous prime is 231621469. The next prime is 231621527. The reversal of 231621487 is 784126132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231621487 - 2⁷ = 231621359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231621287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115810743 + 115810744.

It is an arithmetic number, because the mean of its divisors is an integer number (115810744).

Almost surely, 2^231621487 is an apocalyptic number.

231621487 is a deficient number, since it is larger than the sum of its proper divisors (1).

231621487 is an equidigital number, since it uses as much as digits as its factorization.

231621487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 34.

The square root of 231621487 is about 15219.1158415987. The cubic root of 231621487 is about 614.1290131627.

It can be divided in two parts, 23162 and 1487, that added together give a square (24649 = 157²).

The spelling of 231621487 in words is "two hundred thirty-one million, six hundred twenty-one thousand, four hundred eighty-seven".