21690742258 has 8 divisors (see below), whose sum is σ = 32743350252. Its totient is φ = 10776292176.

The previous prime is 21690742231. The next prime is 21690742259. The reversal of 21690742258 is 85224709612.

It can be written as a sum of positive squares in 2 ways, for example, as 21690514729 + 227529 = 147277^2 + 477^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21690742259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34539085 + ... + 34539712.

Almost surely, 2^21690742258 is an apocalyptic number.

21690742258 is a deficient number, since it is larger than the sum of its proper divisors (11052607994).

21690742258 is a wasteful number, since it uses less digits than its factorization.

21690742258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69078956.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 21690742258 in words is "twenty-one billion, six hundred ninety million, seven hundred forty-two thousand, two hundred fifty-eight".