1642636556 has 24 divisors (see below), whose sum is σ = 3237104640. Its totient is φ = 722566800.

The previous prime is 1642636547. The next prime is 1642636559. The reversal of 1642636556 is 6556362461.

It is a super-2 number, since 2×1642636556² = 5396509710215082272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (1642636559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 600776 + ... + 603503.

It is an arithmetic number, because the mean of its divisors is an integer number (134879360).

Almost surely, 2^1642636556 is an apocalyptic number.

It is an amenable number.

1642636556 is a deficient number, since it is larger than the sum of its proper divisors (1594468084).

1642636556 is a wasteful number, since it uses less digits than its factorization.

1642636556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1204325 (or 1204323 counting only the distinct ones).

The product of its digits is 777600, while the sum is 44.

The square root of 1642636556 is about 40529.4529447413. The cubic root of 1642636556 is about 1179.9053251630.

The spelling of 1642636556 in words is "one billion, six hundred forty-two million, six hundred thirty-six thousand, five hundred fifty-six".