1626397740 has 144 divisors (see below), whose sum is σ = 5394654720. Its totient is φ = 393344640.

The previous prime is 1626397711. The next prime is 1626397757. The reversal of 1626397740 is 477936261.

1626397740 is a `hidden beast` number, since 1 + 6 + 2 + 639 + 7 + 7 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1224957 + ... + 1226283.

It is an arithmetic number, because the mean of its divisors is an integer number (37462880).

Almost surely, 2^1626397740 is an apocalyptic number.

1626397740 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 1626397740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2697327360).

1626397740 is an abundant number, since it is smaller than the sum of its proper divisors (3768256980).

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

1626397740 is a wasteful number, since it uses less digits than its factorization.

1626397740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1972 (or 1967 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 1626397740 is about 40328.6218460289. The cubic root of 1626397740 is about 1176.0043297772.

It can be divided in two parts, 16263 and 97740, that added together give a triangular number (114003 = T₄₇₇).

The spelling of 1626397740 in words is "one billion, six hundred twenty-six million, three hundred ninety-seven thousand, seven hundred forty".