20723451 has 16 divisors (see below), whose sum is σ = 31718400. Its totient is φ = 11789568.

The previous prime is 20723449. The next prime is 20723453. The reversal of 20723451 is 15432702.

It is an interprime number because it is at equal distance from previous prime (20723449) and next prime (20723453).

It is not a de Polignac number, because 20723451 - 2¹ = 20723449 is a prime.

It is a super-2 number, since 2×20723451² = 858922842698802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20723453) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2955 + ... + 7083.

It is an arithmetic number, because the mean of its divisors is an integer number (1982400).

Almost surely, 2^20723451 is an apocalyptic number.

20723451 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20723451 is a deficient number, since it is larger than the sum of its proper divisors (10994949).

20723451 is a wasteful number, since it uses less digits than its factorization.

20723451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4378.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20723451 is about 4552.3017255011. The cubic root of 20723451 is about 274.6759864311.

The spelling of 20723451 in words is "twenty million, seven hundred twenty-three thousand, four hundred fifty-one".