15400020 has 96 divisors (see below), whose sum is σ = 45416448. Its totient is φ = 3894912.

The previous prime is 15399997. The next prime is 15400031. The reversal of 15400020 is 2000451.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 15399969 and 15400005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 121197 + ... + 121323.

It is an arithmetic number, because the mean of its divisors is an integer number (473088).

Almost surely, 2^15400020 is an apocalyptic number.

15400020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15400020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22708224).

15400020 is an abundant number, since it is smaller than the sum of its proper divisors (30016428).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15400020 is a wasteful number, since it uses less digits than its factorization.

15400020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 15400020 is about 3924.2859223048. The cubic root of 15400020 is about 248.7943011760.

Adding to 15400020 its reverse (2000451), we get a palindrome (17400471).

The spelling of 15400020 in words is "fifteen million, four hundred thousand, twenty".