21061629 has 12 divisors (see below), whose sum is σ = 31745376. Its totient is φ = 13430472.

The previous prime is 21061619. The next prime is 21061639. The reversal of 21061629 is 92616012.

21061629 is a `hidden beast` number, since 21 + 0 + 616 + 29 = 666.

It is an interprime number because it is at equal distance from previous prime (21061619) and next prime (21061639).

It is not a de Polignac number, because 21061629 - 2⁴ = 21061613 is a prime.

It is a super-2 number, since 2×21061629² = 887184432267282, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061609) 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, 50667 + ... + 51080.

It is an arithmetic number, because the mean of its divisors is an integer number (2645448).

Almost surely, 2^21061629 is an apocalyptic number.

It is an amenable number.

21061629 is a deficient number, since it is larger than the sum of its proper divisors (10683747).

21061629 is a wasteful number, since it uses less digits than its factorization.

21061629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101776 (or 101773 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21061629 is about 4589.2950439038. The cubic root of 21061629 is about 276.1620425257.

The spelling of 21061629 in words is "twenty-one million, sixty-one thousand, six hundred twenty-nine".