1209623540 has 24 divisors (see below), whose sum is σ = 2599285920. Its totient is φ = 472596768.

The previous prime is 1209623509. The next prime is 1209623549. The reversal of 1209623540 is 453269021.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1209623497 and 1209623506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209623549) 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, 702410 + ... + 704129.

It is an arithmetic number, because the mean of its divisors is an integer number (108303580).

Almost surely, 2^1209623540 is an apocalyptic number.

1209623540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1209623540 is an abundant number, since it is smaller than the sum of its proper divisors (1389662380).

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

1209623540 is a wasteful number, since it uses less digits than its factorization.

1209623540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406591 (or 1406589 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 1209623540 is about 34779.6426088596. The cubic root of 1209623540 is about 1065.4917138387.

It can be divided in two parts, 120962 and 3540, that multiplied together give a triangular number (428205480 = T₂₉₂₆₄).

The spelling of 1209623540 in words is "one billion, two hundred nine million, six hundred twenty-three thousand, five hundred forty".