20520761 has 8 divisors (see below), whose sum is σ = 21912000. Its totient is φ = 19171152.

The previous prime is 20520743. The next prime is 20520767. The reversal of 20520761 is 16702502.

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

It is a cyclic number.

It is not a de Polignac number, because 20520761 - 2¹⁴ = 20504377 is a prime.

It is a super-2 number, since 2×20520761² = 842203264038242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20520767) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9386 + ... + 11363.

It is an arithmetic number, because the mean of its divisors is an integer number (2739000).

Almost surely, 2^20520761 is an apocalyptic number.

It is an amenable number.

20520761 is a deficient number, since it is larger than the sum of its proper divisors (1391239).

20520761 is a wasteful number, since it uses less digits than its factorization.

20520761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20815.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20520761 is about 4529.9846578107. The cubic root of 20520761 is about 273.7775424565. Note that the first 3 decimals are identical.

The spelling of 20520761 in words is "twenty million, five hundred twenty thousand, seven hundred sixty-one".