21769031 has 4 divisors (see below), whose sum is σ = 21993552. Its totient is φ = 21544512.

The previous prime is 21768997. The next prime is 21769039. The reversal of 21769031 is 13096712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21769031 - 2²² = 17574727 is a prime.

It is a super-2 number, since 2×21769031² = 947781421357922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21768985 and 21769003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21769039) 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, 112115 + ... + 112308.

It is an arithmetic number, because the mean of its divisors is an integer number (5498388).

Almost surely, 2^21769031 is an apocalyptic number.

21769031 is a deficient number, since it is larger than the sum of its proper divisors (224521).

21769031 is an equidigital number, since it uses as much as digits as its factorization.

21769031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224520.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21769031 is about 4665.7294177867. The cubic root of 21769031 is about 279.2198991778.

The spelling of 21769031 in words is "twenty-one million, seven hundred sixty-nine thousand, thirty-one".